Clarify and clean up wording in keymap.md, section 0

Compile options can be defined in project Makefile such as UDEFS, UADEFS, UINCDIR, ULIBDIR and ULIBS.

ee8c5ba Remove warnings when NO_DEBUG is defined
a71e6e0 Remove warnings when NO_PRINT is defined

git-subtree-dir: tmk_core
git-subtree-split: ee8c5baecc

97c7ed4 Fix COMMON_DIR in common.mk.

git-subtree-dir: tmk_core
git-subtree-split: 97c7ed4de6

08ce4c3 Add update for chibios in README
30cac1d Merge remote-tracking branch 'flabbergast-tmk_keyboard/chibios'
f218a38 core: Remove unused warning. Fix tmk_keyboard/#293
3e68807 Chibios: add more guards for transmitting (fix a deadlock bug).
cecc807 core: Speed up compilation
d01d959 Merge remote-tracking branch 'upstream/master' into chibios
8ff12ae Merge pull request #230 from jerryen/master
3afb83d core: Add note about sudo and git
2525d5d Chibios: Update to new USB API.
2fc5cd6 Merge branch 'master' into chibios
6f5511a core: Fix variable initialize
02a15fa core: Fix variable init and header include
1833ca1 Merge pull request #292 from obones/command_warning
bc9dc6f Merge pull request #294 from shayneholmes/fix-debug-message
c1b891b Merge pull request #295 from doopai/master
1da837c core: Add macro commands SM(), RM() and CM()
d9d5a93 Add support for storing, restoring and clearing modifiers in macros
4f371c0 core: Add dfu-programmer example to doc/build.md
ba3792e core: Fix doc/build.md
4b99fed remove  SERIAL_SOFT_DEBUG macro
984accb Fix typo in bootmagic debug message
67a7ea1 usb_usb: Fix for keymap editor
2fc9ae4 host_driver is only used if KEYBOARD_LOCK_ENABLE is defined
a35cdea Chibios: add 'core/protocol' to the makefiles' search path.
5ed2fd6 Merge remote-tracking branch 'upstream/master' into chibios
bbc4851 Do timeout when writing to CONSOLE EP queue.
2450559 Remove an errant comma trailing the KC_ERAS macro alias
8465747 Merge pull request #270 from jeffgran/single-tap-toggle
a37339a Merge pull request #271 from jeffgran/default-layer-toggle
8e732f7 core: Update doc/build.md and remove other_projects.md
e47dc15 Workaround for compiler warnings when console disabled.
4184c52 Add maple mini code.
b555238 core: Fix rules.mk for dfu target
26dacf4 add ACTION_DEFAULT_LAYER_TOGGLE to toggle a default layer on/off
83607d9 enable TAPPING_TOGGLE=1 to work correctly
bef3089 Merge branch 'master' into chibios
f7a55fd core: Fix debug print of usb_hid
1402f7d core: Add keycode KC_JPY for JIS
8e3a460 Chibios: Remove the wait in the main loop.
7d41746 ChibiOS: prettify/document sleep_led code.
235cdee ChibiOS: Update infinity bootloader code to match updated ChibiOS.
807bf1e Chibios: Add breathing sleep LED on Kinetis MCUs.
ba3bf7c ChibiOS: make reset request more CMSISy.
bf2ffd4 Add correct chibios/bootloader_jump for infinity KB.
f5e03fd Chibios/usb_main: rename a variable for clarity.
63a330c Fix drop key stroke
d8f5b06 Fix report size of boot protocol.
38abb50 ChibiOS/STM32: send remote wakeup.
6725650 ChibiOS/kinetis: sending remote wakeup.
69f6e54 Chibios: use WFI in idle. WIP suspend stuff.
02f044b Move chibios/cortex selection to local Makefiles.
fa59dfa Rename chibios example keyboard.
5c060de Add eeprom support for chibios/kinetis.
efd0044 Move declaration of keymap_config.
7196b24 Make bootmagic.c code portable (_delay_ms -> wait_ms).
37b15b2 Add missing #include to keymap.c.
31316e3 Merge branch 'master' into chibios
166f312 Fix chibios/usb_main GET_REPORT handing.
57ac6c2 Add ARM Teensies bootloader code.
1758086 Move STM32 bootloader address config to separate .h file.
03bb026 Rename some Makefile defines.
76ba6ac NKRO fixes.
06498f8 Update chibios README.
db0a4f5 Add basic sleep_led for chibios.
c3f930e Move AVR specific sleep_led.c into avr.
4069494 Fix bootloader-jump compiling.
9117f7b Small updates.
269cb85 Implement jump-to-bootloader.
7e81b34 Move chibios to tool.
923a892 Make usb_main more USB_DRIVER #define independent.
aa054f0 Add ChibiOS support (USB stack + support files).
1e3e282 Modularity and gcc warnings fixes.
2f60ce0 Add KEYBOARD_LOCK_ENABLE to makefile

git-subtree-dir: tmk_core
git-subtree-split: 08ce4c3021

Merge flabbergast's chibios protocol into master
https://github.com/flabbergast/tmk_keyboard/tree/chibios

core: Speed up compilation

Add KEYBOARD_LOCK_ENABLE to makefile

Fix warning in command.c

Fix typo in bootmagic debug message