Mrb string value cstr patch

Need mruby-compiler to build mruby-bin-mruby and mruby-bin-mirb for

Proc#curry should preserve lambdas

cross compiles

From the CRuby 2.2.2 Proc#arity documentation:

If the block has optional arguments, returns -n-1, where n is the number
of mandatory arguments, with the exception for blocks that are not
lambdas and have only a finite number of optional arguments; in this
latter case, returns n.

Add :mgem gem loading.

Fix repository link to mruby/mruby

Fix typos in documentation and error messages

[ci skip] Remove some Srting#split samples

mruby not support regexp, so remove these samples.

Time rounding precision

refactor code to call mrb_inspect() instead

mrb_inspect() also calls mrb_obj_as_string() after #inspect to ensure
the mrb_value is a string.

Remove the unused libterminfo detection code.

The detection code is unused even on OpenBSD 5.7,
because of the standard installation is libtermcap be installed, not libterminfo.

This fixes #2829

Tested on Arch Linux (x86_64) & OpenBSD 5.7 (amd64).
Signed-off-by: Huei-Horng Yo <hiroshi@ghostsinthelab.org>

Detect if ncurses' backend is terminfo or termcap.

Borrowed from @mattn's code at:
https://github.com/mruby/mruby/issues/2662#issuecomment-65535705Signed-off-by: Huei-Horng Yo <hiroshi@ghostsinthelab.org>

gsub/sub supports back references in substitutes.  fixes #2816.

This implementation is compatible with CRuby's String#gsub/sub
except \1 ... \9 and \+.  They are useless without Regexp library.

Fix build on MIPS of linux

Added some documentation for some of the functions found in array.h.

MIPS of Linux platform is supported frexpl(3).
This fixes to use the frexpl that are provided with gcc if user wants to build
on MIPS of Linux platform.
Signe-doff-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>