add safety check for bit-reading for headers
refine android build, add TARGET option to specify target in sdk
update README
Merge pull request #323 from huili2/check_bit_read

add safety check for bit-reading for headers
add missed namespace for encoder, remove un-used file
Merge pull request #321 from licaiguo/add-android-target-option

Add android target option
Merge pull request #324 from volvet/add-missed-namespace-for-encoder

add missed namespace for encoder, remove un-used file
fix the crash issues by changing the type iMbWidth & iMbHeight.
Merge pull request #326 from licaiguo/fix-allocate-large-memory

fix the crash issues by changing the type of iMbWidth & iMbHeight.
Ignore project.properties

This file is autogenerated when building nowadays.
Merge pull request #327 from mstorsjo/ignore-android-files

Ignore project.properties
Enable x86 assembly by default if building for x86 android

Most users would probably miss enabling it otherwise.

It can still be disabled manually by passing USE_ASM=No on the
make command line.
Merge pull request #328 from mstorsjo/enable-x86-asm-android

Enable x86 assembly by default if building for x86 android
Merge remote-tracking branch 'upstream/master' into travis.osx