Merge pull request #2059 from cremno/reduce-rstring_ptr-usage

reduce RSTRING_PTR usage
Merge pull request #2060 from cremno/exc_inspect-dup-file

exc_inspect: dup file and check mesg only once
fixed wrong use of pointer reference found by @tsahara; ref #2059
should always initialize header flags for pooled strings
Fix and add test to Proc#inspect .
resolve conflict
Update Language Documentation
Implement switch for line numbers
Update language documentation without line number to reduce update interval in the future
Improve generator to output status
merge @mattn's win-compatibility
OP_EQ系が速くなった
Merge pull request #2063 from bovi/update_language_doc

Improve Language Documentation
Merge pull request #2064 from mirichi/opt_jmp

OP_EQ系が速くなった
fixed typo in opcode.h
Add test for UTF-8 string String#size .
Merge pull request #2065 from take-cheeze/utf8_string_size_test

Add test for UTF-8 string String#size .
Refactor fix_shift_get_width in numeric.c
Refactor lshift in numeric.c
Refactor fix_to_f in numeric.c