Increment to v1.1a, minor compile bug fix, tweaked communication protocol, more docs.

- Incremented to v1.1a, rather than keep 1.0e. This is because there
are existing v1.0 installations. Don’t want to confuse people further.

- Certain version of the Arduino IDE did not like the `inline` in the
function header. Removed from spindle_control files to fix the problem.

- Tweaked the communication protocol slightly. Added message type
indicators for all `[]`bracketed feedback messages. It’s been
problematic for GUI dev to try to determine the context of a message
and how it should be handled. These indictors should help tremendously
to remove context all together.

- Also altered how `$N` startup lines are presented when executed. They
now start with an open chevron ‘>’ followed by the line and an ‘:ok’ to
indicate it executed. The ‘ok’ is on the same line intentionally so it
doesn’t mess up a streaming protocol counter.

- Managed to save a 100+KB from refactoring parts of report.c. (Thanks
Vasilis!) Freed up room to alter the protocol a little.

- Wrote a markdown document on interface messaging to make it clear how
it’s intended to work. See interface.md in /doc/markdown

- Started to pull in some Wiki pages from the old grbl site and
beginning to update them for v1.1.

- Created new commit log for v1.1.

doc/markdown/error_codes.md

@@ -105,20 +105,20 @@ Format - `(v1.0)` `:` `(v0.9)` - `Description`
 
 Format - `Message` - `Description`
 
-- `[Reset to continue]` - Critical event message. Reset is required before Grbl accepts any other commands. This prevents ongoing command streaming and risking a motion before the alarm is acknowledged. Hard or soft limit errors will trigger this event.
+- `[MSG:Reset to continue]` - Critical event message. Reset is required before Grbl accepts any other commands. This prevents ongoing command streaming and risking a motion before the alarm is acknowledged. Hard or soft limit errors will trigger this event.
 
-- `[‘$H’|’$X’ to unlock]`- Alarm message at initialization. All g-code commands and some ‘$’ are blocked until unlocked via homing or $X.
+- `[MSG:‘$H’|’$X’ to unlock]`- Alarm message at initialization. All g-code commands and some ‘$’ are blocked until unlocked via homing or $X.
 
-- `[Caution: Unlocked]` - Alarm unlock $X acknowledgement.
+- `[MSG:Caution: Unlocked]` - Alarm unlock $X acknowledgement.
 
-- `[Enabled]` - Indicates Grbl’s check-mode is enabled.
+- `[MSG:Enabled]` - Indicates Grbl’s check-mode is enabled.
 
-- `[Disabled]` - Indicates Grbl’s check-mode is disabled. Grbl is automatically reset afterwards.
+- `[MSG:Disabled]` - Indicates Grbl’s check-mode is disabled. Grbl is automatically reset afterwards.
 
-- `[Check Door]` - Safety door detected as open. This message appears either immediately upon a safety door ajar or if the safety is open when Grbl initializes after a power-up/reset.
+- `[MSG:Check Door]` - Safety door detected as open. This message appears either immediately upon a safety door ajar or if the safety is open when Grbl initializes after a power-up/reset.
 
-- `[Check Limits]` - If Grbl detects a limit switch is triggered after power-up/reset and hard limits are enabled, this will appear as a courtesy message.
+- `[MSG:Check Limits]` - If Grbl detects a limit switch is triggered after power-up/reset and hard limits are enabled, this will appear as a courtesy message.
 
-- `[Pgm End]` - M2/30 program end message to denote g-code modes have been restored to defaults according to the M2/30 g-code description.
+- `[MSG:Pgm End]` - M2/30 program end message to denote g-code modes have been restored to defaults according to the M2/30 g-code description.
 
-- `[Restoring defaults]` - Acknowledgement message when restoring EEPROM defaults via a `$RST=` command.
+- `[MSG:Restoring defaults]` - Acknowledgement message when restoring EEPROM defaults via a `$RST=` command.