add json to build scripts

doc/bugs/Build_error_on_Mac_OSX_10.6.mdwn

@@ -7,3 +7,5 @@ Utility/JSONStream.hs:14:8:
     Could not find module `Text.JSON':
       Use -v to see a list of the files searched for.
 make: *** [git-annex] Error 1
+
+> Updated the instructions. [[done]] --[[Joey]] 

doc/install/Fedora.mdwn

@@ -11,6 +11,7 @@ sudo cabal install SHA
 sudo cabal install dataenc
 sudo cabal install monad-control
 sudo cabal install HTTP
+sudo cabal install json
 sudo cabal install hS3
 
 git clone git://git-annex.branchable.com/

doc/install/OSX.mdwn

@@ -13,6 +13,7 @@ sudo cabal install SHA
 sudo cabal install dataenc
 sudo cabal install monad-control
 sudo cabal install HTTP
+sudo cabal install json
 sudo cabal install hS3 # optional
 
 # optional: this will enable the gnu tools, (to give sha224sum etc..., it does not override the BSD userland)