bug fix: the argument of '--sysroot' option should be followed '=' character.
bug fix: add new option '-mandroid' into CFLAGS and same options are applied into LDFLAGS.
refactoring
mrbc: exit if outfile is specified multiple times
unify mrb_ary_new{,_elts,_from_values}; mrb_ary_from_values() is a winner
Add String#dump method.
Merge pull request #965 from cremno/mrbc-multiple-outfiles-mem-leak

mrbc: exit if "-o" is specified multiple times
Merge pull request #966 from monaka/pr-add-dump-method-to-String-class

Add String#dump method.
add "strip" family to String.
add mrbgems/ext/mruby-numeric, and method: Integer#chr
add Integer#chr test case: multibyte (raise RangeError)
fix comment
Fixed #969
Merge pull request #967 from iij/pr-string-strip

add "strip" family methods of String to mruby-string-ext
Merge pull request #968 from kouki-o-iij/pr-mrbgem-numeric-ext

add mrbgems/ext/mruby-numeric, and method: Integer#chr
Merge pull request #970 from masuidrive/fix_building_script

Fixed #969
OP_ARRAY may overflow ARG_C
Merge branch 'master' of github.com:mruby/mruby
define and use print format macros for mrb_int

For portability: %ld can't be used to print a 64-bit mrb_int on
WIN(32|64) because long is 32-bit wide.
add a new feature to select the target architecture.