remove Class#alloc method
Merge branch 'master' of github.com:mruby/mruby
Merge branch 'master' of github.com:mruby/mruby
Merge branch 'master' of github.com:mruby/mruby
Added test case for String#start_with? with string of length 1.
Fix for string-length-related issue in String#start_with? logic.
Added test case for String#end_with? with string of length 2.
Fix for string-length-related issue in String#end_with? logic.
Refactor of String#end_with? comparison logic.
Refactor of String#start_with? comparison logic.
add mrb_string_type().
Check type of arguments for #start_with and #end_with.
Fix a problem of 'z' option and shared string
add Exception#backtrace
Merge branch 'get-backtrace' of https://github.com/wanabe/mruby into wanabe-get-backtrace
undef print_backtrace_i() unless ENABLE_STDIO
add cast to void*
do not use mrb_alloca() that keeps memory until mrb_state freed
Merge pull request #1487 from h2so5/z-option-with-shared-string

Fix a problem of 'z' option and shared string
support file extension .cpp/.cxx in mrbgem and tool