dev-util/codeblocks: unbundle dev-util/astyle lib

dev-util/codeblocks: unbundle dev-util/astyle lib

Unbundle the dev-util/astyle library in favor of system installed
by adding it as build dependency ( >=dev-util/astyle-3.0.1-r1:0= ):

1. patching (update) the Codeblocks Astyle plugin to be compatible with dev-util/astyle-3.1:
"codeblocks-17.12_update_astyle_plugin_to_v3.1.patch" that is taken from upstream:

https://sourceforge.net/p/codeblocks/code/11266/

  * updated astyle plugin to v3.1
  * removed obsolete astyle options
  * added new astyle options
  Authored by: jenslody 2018-01-15

(using conditional patching depends on if '>=dev-util/astyle-3.1' is installed in system);

2. use sub-sloting of dev-util/astyle to force rebuild Codeblocks on system update
if sub-slot of dev-util/astyle is changed;

3. remove KEYWORD "arm" to avoid repoman QA warning about "dependency.bad" and
"dependency.badindev" due to dev-util/astyle dependency doesn't have this KEYWORD.

Closes: https://bugs.gentoo.org/383037
Closes: https://bugs.gentoo.org/656758