[zanata/zanata-server] 329eaf: fix(ZNTA-628): fall back on locale's plural forms

[GitHub]

  Branch: refs/heads/ZNTA-628-empty-plural-forms
  Home:   https://github.com/zanata/zanata-server
  Commit: 329eaf567f087b2f1fdb35ef2c6e20952774006b
      https://github.com/zanata/zanata-server/commit/329eaf567f087b2f1fdb35ef2c6e20952774006b
  Author: Sean Flanigan <sflaniga at redhat.com>
  Date:   2015-08-20 (Thu, 20 Aug 2015)

  Changed paths:
    M zanata-war/src/main/java/org/zanata/rest/service/ResourceUtils.java
    M zanata-war/src/test/java/org/zanata/rest/service/ResourceUtilsTest.java

  Log Message:
  -----------
  fix(ZNTA-628): fall back on locale's plural forms

Fall back on locale's plural forms when plurals header is empty.
Also simplify the code and improve log messages.