fix DEFAULT_HIDE_RULES so that unittest lib will not be overwritten
move gravatar utility from railgun.common to railgun.website
move gravatar utility from railgun.common to railgun.website
add user filter on admin handin list
minor fix
minor fix
minor fix
minor fix
minor fix
api docs on the way
api common part is finished.
minor fix
minor fix
add makepdf.sh to use xelatex, so that chinese characters can show in pdf
minor fix to support build on rtd.org
minor fix to support build on rtd.org
minor fix to support build on rtd.org
minor fix to support build on rtd.org
minor fix to support build on rtd.org
minor fix to support build on rtd.org