Refactor names in translation memory entities.
Language code fixes and table renaming.
Merge branch 'tm-import' of github.com:zanata/zanata into tm-import

Conflicts:
	zanata-war/src/main/java/org/zanata/rest/service/ExportTMXTransUnitStrategy.java
	zanata-war/src/main/java/org/zanata/rest/service/TranslationMemoryResourceService.java
	zanata-war/src/test/java/org/zanata/rest/service/ExportTransUnitTest.java