Replace malloc with mrb_malloc in mrbc

Add NotImplementedError for Kernel.` and Kernel#`

Show version only once with '-v' option in mruby/mrbc

Add validation for C language symbol name

Fix mirb to use readline

although I understand the intntion of 039679f1, consuming all memory in the test program is not a good idea

Add more ISO conformance tests.

Add ARGV constant. It is not required by ISO. Compatibility with CRuby.

Fix a memory leak in mirb

Add "test runner" support for cross builds.

Change mruby-random License to MIT

refs: http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/MT2002/license.html

Fix checking for heredoc in mirb

Support $0 variable.

 "test runner" means target simulator like QEmu, GDB sim, and so on. Also "test runner" might be debug agents for real targets.
If you do not setup test_runner, Rake will work same as before.

stdint header seems required on osx for uint8_t

Define isascii for C99

Improve checking for unterminated string in mirb

Modified build dependency to exclude 'LEGAL' from libmruby archive.