nregs size was too big (off by one); close #1137
target_class should not be TT_ICLASS; close #1152
although I understand the intntion of 039679f1, consuming all memory in the test program is not a good idea
Add NotImplementedError for Kernel.` and Kernel#`
Show version only once with '-v' option in mruby/mrbc
preparation for tail call optimization (still has bugs)
Add validation for C language symbol name
Fix mirb to use readline
Merge branch 'master' of github.com:mruby/mruby
Merge pull request #1165 from iij/pr-fix-mirb

Fix mirb to use readline
Merge pull request #1164 from h2so5/add-validation-for-c-symbol

Add validation for C language symbol name
Merge pull request #1163 from h2so5/show-version-once

Show version only once with '-v' option in mruby/mrbc
Merge pull request #1162 from h2so5/error-for-external-command-execution

Add NotImplementedError for Kernel.` and Kernel#`