nzc bug fix and clear
add according to review opinion
Merge pull request #486 from huili2/nzc_bug_fix

nzc bug fix and clear
clean redundant checks in decoder
refactor ME for easier adding other search methods
Merge pull request #488 from licaiguo/clean-redundant-check

clean redundant checks in decoder
Fix a mismatched ifdef comment

This is an ifdef block for HAVE_NEON.
Merge pull request #492 from mstorsjo/fix-ifdef-comment

Fix a mismatched ifdef comment
Fix a typo in a macro name, EXTENTION -> EXTENSION
add basic me test
Merge pull request #495 from sijchen/add_me_test11

[Encoder UnitTest] add basic me test
Merge pull request #493 from mstorsjo/fix-macro-typo

Fix a typo in a macro name, EXTENTION -> EXTENSION
Merge pull request #489 from sijchen/me_refactor22

refactor ME for easier adding other search methods