main/onboard: new aport (!370)

Currently we're using matchbox-keyboard as on screen keyboard. However,
onboard seems to be a better alternative to, it has auto-show, word
suggestions, themes and settings you can choose. So far the best OSK out
there on the market.

There are a few minor issue such as word suggestions doesn't work (not
sure why, but i assume that onboard doesn't know about the program that
was in front of it), sound feedback doesn't work at all due to missing
sound despite it exists in
/usr/share/sounds/freedesktop/stereo/onboard-key-feedback.oga. Other
than that, I haven't found any issue while testing.

Tested on qemu-amd64.

main/onboard/APKBUILD

@@ -0,0 +1,28 @@
+# Contributor: Danct12 <danct12@disroot.org>
+# Maintainer: Danct12 <danct12@disroot.org>
+pkgname=onboard
+pkgver=1.4.1
+pkgrel=0
+pkgdesc="On-screen keyboard useful on tablet PCs or for mobility impaired users"
+arch="all"
+url="https://launchpad.net/onboard"
+license="GPL"
+depends="python3 hunspell gtk+3.0 iso-codes libcanberra libxkbfile py3-cairo py3-dbus py3-gobject3 dconf ncurses gsettings-desktop-schemas librsvg"
+makedepends="python3-dev py3-dbus py3-setuptools py3-distutils-extra bash bash-dev gtk+3.0-dev libxkbfile-dev dconf-dev libcanberra-dev hunspell-dev eudev-dev"
+source="https://launchpad.net/${pkgname}/${pkgver%.*}/${pkgver}/+download/${pkgname}-${pkgver}.tar.gz
+        glibc-musl-error.patch"
+builddir="$srcdir/${pkgname}-${pkgver}"
+subpackages="$pkgname-doc $pkgname-lang"
+
+build() {
+	cd "$builddir"
+	python3 setup.py build
+}
+
+package() {
+	cd "$builddir"
+	python3 setup.py install --prefix=/usr --root="$pkgdir" --optimize=1
+}
+
+sha512sums="ed75c1dce893e3420ecf532faffb15efc9fba56cf6622b03fe5e1cebb88d32304636b0268e4b8b75dc0eb6d7bfc8602c4a93a90bdeb8cd960d3447d16acc7463  onboard-1.4.1.tar.gz
+23742c38f877fc31260d4d7d3ff38c8d72541a77e099183d6633de74bcb223bbd34cedd88016f043867b2571f1196b59a3378a94186b468dbaa7a5d00661065a  glibc-musl-error.patch"

main/onboard/glibc-musl-error.patch

@@ -0,0 +1,62 @@
+diff --git a/Onboard/pypredict/lm/lm.cpp b/Onboard/pypredict/lm/lm.cpp
+index 2e64296..081b3fb 100644
+--- a/Onboard/pypredict/lm/lm.cpp
++++ b/Onboard/pypredict/lm/lm.cpp
+@@ -19,7 +19,7 @@
+ 
+ #include <stdlib.h>
+ #include <stdio.h>
+-#include <error.h>
++
+ #include <algorithm>
+ #include <cmath>
+ #include <string>
+@@ -37,7 +37,7 @@ StrConv::StrConv()
+     if (cd_mb_wc == (iconv_t) -1)
+     {
+         if (errno == EINVAL)
+-            error (0, 0, "conversion from UTF-8 to wchar_t not available");
++            fprintf (stderr, "conversion from UTF-8 to wchar_t not available");
+         else
+             perror ("iconv_open mb2wc");
+     }
+@@ -45,7 +45,7 @@ StrConv::StrConv()
+     if (cd_wc_mb == (iconv_t) -1)
+     {
+         if (errno == EINVAL)
+-            error (0, 0, "conversion from wchar_t to UTF-8 not available");
++            fprintf (stderr, "conversion from wchar_t to UTF-8 not available");
+         else
+             perror ("iconv_open wc2mb");
+     }
+diff --git a/Onboard/pypredict/lm/lm_dynamic.cpp b/Onboard/pypredict/lm/lm_dynamic.cpp
+index 7c62824..da8cfd0 100644
+--- a/Onboard/pypredict/lm/lm_dynamic.cpp
++++ b/Onboard/pypredict/lm/lm_dynamic.cpp
+@@ -17,7 +17,7 @@
+  * along with this program. If not, see <http://www.gnu.org/licenses/>.
+  */
+ 
+-#include <error.h>
++
+ 
+ #include "lm_dynamic.h"
+ 
+@@ -91,7 +91,7 @@ LMError DynamicModelBase::load_arpac(const char* filename)
+                     int ngrams_read = get_num_ngrams(current_level-1);
+                     if (ngrams_read != ngrams_expected)
+                     {
+-                        error (0, 0, "unexpected n-gram count for level %d: "
++                        fprintf (stderr, "unexpected n-gram count for level %d: "
+                                      "expected %d n-grams, but read %d",
+                               current_level,
+                               ngrams_expected, ngrams_read);
+@@ -105,7 +105,7 @@ LMError DynamicModelBase::load_arpac(const char* filename)
+                     if (ntoks < current_level+1)
+                     {
+                         err_code = ERR_NUMTOKENS; // too few tokens for cur. level
+-                        error (0, 0, "too few tokens for n-gram level %d: "
++                        fprintf (stderr, "too few tokens for n-gram level %d: "
+                               "line %d, tokens found %d/%d",
+                               current_level,
+                               line_number, ntoks, current_level+1);