Misc: Adding TODO.sunyc.
Misc: Untrack auto-generated files from git.
Comp: IPV6 complie fix.
Comp: Test and set std=c99 mode on supported platform.

Also setting Wextra in development mode.
Comp: Test and set -march=native
Comp: Detects Linux and x86-64 environment.
Comp: Fix random compile warnings.
Comp: TYPE_MOD_ARRAY overflow signed short warning.
Comp: fixes 64bit warnings on IR code generation.
Comp: Fix const and sign related warnings.
Misc: int overflow if max_eval_cost is set high.
Misc: Fix comment for HEARTBEAT_INTERVAL in options.h
Misc: use INT_MAX for array size limit
LPC: Apply cache position on permission problem.

Calling a function with necessary permission will cause apply_cache to
be filled with a "non-exist" result, and later calls with enough
permission will still not be able to call it.

Fixed by explicitly return as runtime problem on access permission denied.
It also skip the cache filling on such errors.
LPC: float literals should be parsed as double.
LPC: Correctly handle 64bit defines.

Also expose standard limit __INT_MAX__, __INT_MIN__,
__FLT_MAX__, __FLT_MIN__ as predefine.
Test: Update testsuite config to correctly launch.
Test: Improve logging for tests in testsuite.
Test: LPC int/float correctness verification.

It will pass as long as it is stored as C 64-bit int & double,
as well as parser correctly parse constant literals.
Test: Fix "speed" command in testsuite.

And update motd to show two new commands.