refactor ME for easier adding other search methods
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