Add Array#keep_if

Use mrb_int in mrbgem rest arguments getting.

Fix MSVC warnings for error.c

Support file name and line number argument in eval.

RRange excl flag use mrb_bool insteard of int

Refactoring OP_CALL

Refactoring Array#__svalue

Only a nil binding will be supported.

By reordering parsing string with mrb_parser_parse won't always start with line 1.

Fix MSVC warning for backtrace.c

Range#each fixnums are special

Add Array#delete_if

Fix Array#fill bug and behavior

Remove attention about mrbgem dependecy.

Update documentation of `MRuby::Gem::Specification#add_dependency`.

Fix MSVC warning for gc.c

Implement default gem info to use when there is no depending gem loaded.