Create a unified readme file for the OS/2 versions of Mozilla apps.
[OS/2] Follow-up to creation of BinaryPath.h.
[OS/2] Fix invoke_copy_to_stack() on GCC.
Bug670004 [OS/2] build break in uriloader due to a missing variable after preferences conversion.
[OS/2] Switch to more modern 4.1+ TCP/IP stack by removing TCPV40HDRS define.
[OS/2] Fix debug build.
[OS/2] Disable downloadable fonts as it is unsupported and causes crahses otherwise.
[OS/2] 573408 - fix a crash in PMMERGE.DLL when a window posting a message closes.
[OS/2] Stop duplicating entries in a parent window's list of children.
Fix calling convention conflicts of NPN_xxx funciton pointer.
Put a 1-byte length variable and a 1-byte family variable on OS/2.

OS/2 TCP/IP toolkit require a 1-byte length variable and a 1-bytet.
family variable at first of struct sockaddr. But nspr4 puts a 2-byte
family variable at first.
Because of this, connect() and other APIs fails to work.
Guard IPC sensitive code in manifest parser with MOZ_IPC.

This is needed since IPC is not functioning well on OS/2 so far.
[OS/2] Add support for OS/2 to chromium bits.
Guard IPC sensitive code everywhere in sources with MOZ_IPC define.

If MOZ_IPC is not defined, this effectively disables running tabs and
plugins in separate processes. Which in turn makes it possible to build
the browser on OS/2 where IPC implementation is not complete yet.