Adding stricter validation checks to various symbol parser functions.

More specifically, the validation of the following record types is improved:
 - FILE records
 - FUNC records
 - Line record
 - PUBLIC records

Adding unittests.
Review URL: https://breakpad.appspot.com/632003

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1217 4c0a9323-5329-0410-9bdc-e9ce6186880e
3 files changed