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.
Merge pull request #140 from sunyc/master

Changes for 3.0 alpha7.2
Update description for query_ip_name and query_ip_number.
Update release version to alpha7.3
Issue #84, message loss on failed login.

Fix issue #84. When object is destructed during login phase, the
buffered message will be correctly sent out before connection
is terminated.
unique_mapping(): Fix crash when callback returns new array or mapping.
Source formating.
Merge pull request #141 from sunyc/master

Changes for 3.0 alpha 7.3
Update readme.
Moved some options into options_internal.h
Add warning for extra defines in local_options.
Fix memory corruption in TELNET environment negotiation.
format source.
Fix bug in read_file() for zero length file.
Merge pull request #143 from sunyc/master

More changes for alpha7.3