Ncurses-based CTK backend for the native platform.
ctk-curses: Add mouse support to the ncurses CTK backend.
ctk-curses: Cleanup + fixes

* Cleanup
* Fix warnings
* Fix indentation
* Only wait 1ms for keyboard timeout
* Hide text cursor
* Pump mouse events just in case
* Add F9 as menu key since F10 is used as menu trigger by Gnome
ctk-curses: fix build

Including curses.h in contiki-conf.h (required for COLOR_* defines)
induced a symbol name clash with neighbor-attr.c on "timeout".

Renamed timeout to neighbor_timeout.
ctk-curses: Enable screensaver
ctk-curses: Add configuration for various apps
ctk-curses: Cleanup
Fix a mismatch between declaration and definition
ctk-curses: Introduce CURSES_LIB makefile variable

This should allow overriding it depending on $(HOST_OS).
ctk-curses: Remove extra mouse events pumping loop

It was added to avoid getting garbage keyboard input in some cases,
however it seems not to happen very often and might be the cause
of hang in OSX. If garbage input happens again we can always try
to pump a single event each time instead of looping anyway.
ctk-curses: Guard ncurses-specific mouse function calls

The mouse support is ncurses-specific so guard it with proper #ifdef.
ctk-curses: add CURSES_LIB to TARGET_LIBFILES, not LDFLAGS

It seems TARGET_LIBFILES is used at the end of the link command,
unlike LDFLAGS, which should help when only a static curses lib is
available, like on Haiku.
ctk-curses: C89

At least Haiku still uses gcc2 by default.
ctk-curses: Introduce CTK-specific color names

Since ncurses also defines COLOR_BLACK and friends, and we want
to avoid including curses.h in contiki-conf.h, define CTK_COLOR_*
constants and map them to curses colors in ctk-curses.c.
ctk-curses: Revert "ctk-curses: fix build"

This reverts commit 9ffaa964753f87e23c7f31d178e0d0639f39ab2c.

Since we do not include curses.h anymore there shouldn't be any name clash.
win32: Prefix color names with CTK_

For consistency with ctk-curses, prefix CTK colors with CTK_.

Also introduce COLOR_BG to make it easier to change the widgets
background at once.
Update to markdown

- Spellchecking
- Update plain text to github markdown
Rename to md
Merge pull request #185 from g-oikonomou/bug-fixes/cmd-handler-fix

Fix a mismatch between declaration and definition
ctk-curses: add some comments for clarity