RC LOWBR mode merge
avoid QP sudden fluctates
add UT for PredMv in decoder
add uiMaxNalSize to support the maximum nal size setting
Merge pull request #559 from huili2/UT_PredMv

add UT for PredMv in decoder
Merge pull request #549 from lyao2/rc_tune

RC LOWBR mode merge
Merge pull request #560 from ruil2/encoder_nal

add uiMaxNalSize to support the maximum nal size setting
Move the RC_MODES enum to the public header

This allows users to know what values to set for the iRCMode
parameter.
Make the iRCMode field use the RC_MODES type instead of plain int

This makes it even clearer for users about how to set this field.
Merge pull request #561 from mstorsjo/use-rc-enum

Make the RC_MODES enum public, use it for the iRCMode field
Add checking directional MV in ME initial point
Merge pull request #564 from sijchen/me_rfr56

[Encoder ME] Add checking directional MV in ME initial point
Better error reporting in mktargets.py
use overwrite for scene change detector
Fix line endings in manifest files

Fixes build error in Android getting TOOLCHAINPREFIX
in build/platform-android.mk:

$NDKROOT/build/gmsl/__gmsl:512: *** non-numeric second argument to `wordlist' function: ''.  Stop.
Merge pull request #567 from ylatuya/android

Fix line endings in manifest files
Fix Android build setting minSdkVersion

Beside changing line endings in (see: 973a16) it's also
required to set a minimum Sdk version in the manifest
Merge pull request #568 from ylatuya/android

Fix Android build setting minSdkVersion
Merge pull request #565 from varunbpatil/errstr

Better error reporting in mktargets.py
fix android build for mini-sdk virsion issue