Revert "Deprecate ignoreErrors, see #73"

This reverts commit 34c3b3aacb05d5e863dc9cf38d22326d7d8acf64.

Conflicts:
	src/raven.js
Revert "Removing ignoreErrors, explicitly only filter "Script error.""

This reverts commit 4b4514c7205b0511feb55af93fece2f50fc45e87.