Merge branch 'ww2.5.1.3' of https://github.com/openwebwork/webwork2-dev into ww2.5.1.3
Merge pull request #91 from mgage/ww2.5.1.3

Allow knowls to use base64 encoding.  Add achievements.  Add make text() to PG.
Merge pull request #93 from goehle/ww2.5.1.3

Achievements
add maketext calls to allow localization
add maketext calls to UserList.pm in order to allow localization
add maketext calls around some strings to allow localization
some strings are not localized yet
add maketext calls around some strings in Hardcopy.pm to allow localization
some of these calls (marked with FIXME) seem not to work; I do not know why
add maketext calls to Stats.pm to allow localization
add maketext calls around some strings in Config.pm to allow localization
Merge pull request #95 from heiderich/ww2.5.1.3

Localization