Adding Chinese translation prepared by Liping Chen, MSU
Merge pull request #22 from openwebwork/release/2.7

Release/2.7
Make OPL the default library instead of NPL

This addresses issue #85
Tiny fix in Tags module
Fixed typo
Add explanations for 'avoid_recording_answers' and 'don't_log_answers'.

The first gives permission to the user to NOT have their grades recorded.
The second means that those users and higher do not have their answers logged in the logfiles or in the pastAnswer database.  This can be used to keep TA and instructor answers from corrupting the data collected in those files.
Use internal WWsafe.pm instead of system Safe.pm
Add JSON  requirement for use with Sage calls
Fix default address for libraries.

correct library to libraries
Obtain version number from file VERSION (variable name: $WW_VERSION)
Merge branch 'hotfix1' of http://github.com/openwebwork/webwork2 into develop_tmp

Conflicts:
	conf/localOverrides.conf.dist
Merge branch 'develop' into hotfix0

Conflicts:
	conf/localOverrides.conf.dist
Clean up comments about configuring the path to OPL or NPL
In library browser 1: watermark of new set name instead of text and
boxes around more like this groups.  Also, minor improvement to Tag
reading.
Merge branch 'develop' of github.com:openwebwork/webwork2 into develop
Some OPL problems now have a "level" -- add search capability to
advanced search panel of library browser 1
Make default to assign only to the current user when importing a set def file
Set effective permissions during hardcopy creation

Previously, generating a hardcopy wouldn't include the modified problem header
(which lists the pg file path) even though the effective user had permission to
see this information. This was because the hardcopy generation omitted the
value from the environment and this commit adds the missing value.
Merge pull request #86 from openwebwork/hotfix1

Hotfix1
Merge pull request #90 from jwj61/develop

Improvements related to OPL and  library browser 1