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.

grbl/system.c

@@ -97,11 +97,12 @@ void system_execute_startup(char *line)
   uint8_t n;
   for (n=0; n < N_STARTUP_LINE; n++) {
     if (!(settings_read_startup_line(n, line))) {
-      report_status_message(STATUS_SETTING_READ_FAIL);
+      line[0] = 0;
+      report_execute_startup_message(line,STATUS_SETTING_READ_FAIL);
     } else {
       if (line[0] != 0) {
-        printString(line); // Echo startup line to indicate execution.
-        report_status_message(gc_execute_line(line));
+        uint8_t status_code = gc_execute_line(line);
+        report_execute_startup_message(line,status_code);
       }
     }
   }