osx: Use applespell enchant backend

And fix enchant loading backends in the bundle

osx/hexchat.bundle

@@ -23,9 +23,9 @@
   <binary>
     ${prefix}/lib/libenchant.dylib
   </binary>
-  <data>
-    ${prefix}/share/myspell/dicts
-  </data>
+  <binary>
+    ${prefix}/lib/enchant/libenchant_applespell.so
+  </binary>
 
   <binary dest="${bundle}/Contents/MacOS">
     ${prefix}/bin/python

osx/launcher.sh

@@ -22,6 +22,7 @@ bundle_bin="$bundle_res"/bin
 bundle_data="$bundle_res"/share
 bundle_etc="$bundle_res"/etc
 
+export PREFIX="$bundle_res"
 export DYLD_LIBRARY_PATH="$bundle_lib"
 export XDG_CONFIG_DIRS="$bundle_etc"/xdg
 export XDG_DATA_DIRS="$bundle_data"