rewrote mrb_any_to_s

use %p instead of %lx to prevent truncation and for consistency
Merge pull request #823 from cremno/mrb_any_to_s-rewrite

mrb_any_to_s rewrite
Add semi-colon after the statement.
Merge pull request #824 from monaka/pr-add-semicolon

Add semi-colon after the statement.
changing Make_Data_Struct API; you need to modify your code that uses Make_Data_Struct; close #821
Change task rule based on build_dir so main rules don't clobber gem rules.
Ignore empty gem
Merge pull request #828 from mattn/ignore_empty_gem

Ignore empty gems
Merge pull request #825 from carsonmcdonald/gembuildfix

Change task rule based on build_dir so main rules don't clobber gem rules
Fix incorrect index use. nerr was being used for warning buffer check.
Merge pull request #830 from carsonmcdonald/warncheckfix

Fix incorrect index use. nerr was being used for warning buffer check.
Don't overwrite ciidx if it is already set.
Add documentation for Android toolchain
add mrbtest verbose mode ('-v' option)
"for i in (1..12/5); p i ; end" should not print "3"
Merge pull request #832 from bovi/compile-readme

Add documentation for Android toolchain
Merge pull request #833 from iij/pr-mrbtest-verbose

add mrbtest verbose mode ('-v' option)
Merge pull request #831 from carsonmcdonald/ciidxfix

Don't overwrite ciidx if it is already set.
Merge branch 'master' of github.com:mruby/mruby
should adjust stack size when irep->nregs is larger than allocate size; close #835