Merge pull request #136 from sunyc/master

More changes to be included in alpha7
Merge pull request #137 from sunyc/master

More changes for alpha7
Merge pull request #138 from sunyc/master

alpha 7.1
Update changelog for alpha7.1
local options for pkuxkx.net, the best free chinese mud in PRC.
Merge pull request #139 from pkuxkxjason/next-3.0

local options for pkuxkx
Replace backtick with normal quote in the doc.
Archive some old docs.
Bump version to 3.0-alpha7.2
unique_mapping: Fix crash when callback returns non-shared string.
Update change log for alpha7.2.