build: changed detection for i686/x86_64

Fixes compilation/feature detection on arm.
Merge pull request #929 from bmiklautz/armbuild

build: changed detection for i686/x86_64
added missing defined() in #elif

gcc >= 4.4 requires a condition in #elif.
Merge pull request #930 from bmiklautz/elif

added missing defined() in #elif
primitives: return value to fix compiler warning
include: add various missing extern C decls.
include/winpr/pool.h: fix windows build.
aFreeRDP: initial release

This is the initial release of aFreeRDP the FreeRDP Android client.
For build instructions have a look to docs/README.android.
Merge pull request #933 from thinstuff/android

aFreeRDP: initial release
Merge branch 'master' of github.com:FreeRDP/FreeRDP