core: add C++ compiler and CppUTest for tests in README
tests: add TODO comments for missing tests
core: fix example in comment of function string_replace_regex
core: check that regex is not NULL in function string_replace_regex
tests: add tests of function string_replace_regex
relay: fix crash when an IRC "MODE" command is received from client without arguments
relay: remove dead assignment
relay: fix memory leak when receiving commands from client (weechat protocol)
relay: fix memory leak when receiving several lines from client (weechat protocol)
relay: fix memory leak during handshake on websocket
exec: invert a condition to make code more readable
core: fix bug with several arguments for command /buffer clear|hide|unhide
core: fix memory leak when removing script files
irc: fix memory leak in CTCP answer
core: fix memory leak in completion of config options values
core: fix memory leak on /upgrade when file signature in upgrade file is invalid
logger: fix memory leaks in backlog
core: return immediately if localtime fails in window scroll
core: fix zero-length malloc of an hashtable item with type "buffer"
core: remove dead assignment when converting mouse code