Set nil to uninitialized members
Merge pull request #922 from skandhas/pr-format-vm-source

format some source code (vm.c)
Merge branch 'pluggable_struct' of https://github.com/mattn/mruby into mattn-pluggable_struct
internal array should be pudated using mrb_ary_set()
fix indent in struct.c
remove struct RStruct, use RArray instead
replace instance_of check with structure check
Merge branch 'master' of github.com:mruby/mruby
Fix two typos
Merge pull request #924 from carsonmcdonald/timetypos

Fix two typos
use TT_ARRAY instead of TT_DATA
Remove unused var sv
mrb_open takes no arguments: (void) instead of ()
string interpolation in regex
remove installing executable first to avoid text-file-busy when investigating on debugger
bugfix: assert_raise
Merge pull request #925 from carsonmcdonald/rmunusedvar

Remove unused var sv
Merge pull request #927 from iij/pr-assert-raise-bugfix

bugfix: assert_raise
cleanup: delete commented out match_op() from parse.y
Adjust some indents