Generate API docs from source code comments (#2491)

* Generate api docs from source code

* Add a bunch of doxygen comments

* more doxygen comments

* Add the in-progress api docs

* script to generate docs from travis

* Add doc generation to the travis job

* make travis_docs.sh commit the work it does

* make sure the docs script exits cleanly

1 files changed, 54 insertions, 0 deletions

diff --git a/docs/api_midi_util.md b/docs/api_midi_util.md
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+# group `midi_util` {#group__midi__util}
+
+## Summary
+
+ Members                        | Descriptions                                
+--------------------------------|---------------------------------------------
+`enum `[`midi_packet_length_t`](#group__midi__util_1gae29ff56aee2b430ffe53933b97e5e79e)            | An enumeration of the possible packet length values.
+`public bool `[`midi_is_statusbyte`](#group__midi__util_1ga12e3b42ff9cbb4b4f2bc455fc8743ee5)`(uint8_t theByte)`            | Test to see if the byte given is a status byte.
+`public bool `[`midi_is_realtime`](#group__midi__util_1gad2f52c363e34a8000d80c983c324e2d7)`(uint8_t theByte)`            | Test to see if the byte given is a realtime message.
+`public `[`midi_packet_length_t`](#group__midi__util_1gae29ff56aee2b430ffe53933b97e5e79e)` `[`midi_packet_length`](#group__midi__util_1gaa168b43af6ae9de0debce1625e4b8175)`(uint8_t status)`            | Find the length of the packet associated with the status byte given.
+
+## Members
+
+#### `enum `[`midi_packet_length_t`](#group__midi__util_1gae29ff56aee2b430ffe53933b97e5e79e) {#group__midi__util_1gae29ff56aee2b430ffe53933b97e5e79e}
+
+ Values                         | Descriptions                                
+--------------------------------|---------------------------------------------
+UNDEFINED            | 
+ONE            | 
+TWO            | 
+THREE            | 
+
+An enumeration of the possible packet length values.
+
+#### `public bool `[`midi_is_statusbyte`](#group__midi__util_1ga12e3b42ff9cbb4b4f2bc455fc8743ee5)`(uint8_t theByte)` {#group__midi__util_1ga12e3b42ff9cbb4b4f2bc455fc8743ee5}
+
+Test to see if the byte given is a status byte.
+
+#### Parameters
+* `theByte` the byte to test 
+
+#### Returns
+true if the byte given is a midi status byte
+
+#### `public bool `[`midi_is_realtime`](#group__midi__util_1gad2f52c363e34a8000d80c983c324e2d7)`(uint8_t theByte)` {#group__midi__util_1gad2f52c363e34a8000d80c983c324e2d7}
+
+Test to see if the byte given is a realtime message.
+
+#### Parameters
+* `theByte` the byte to test 
+
+#### Returns
+true if it is a realtime message, false otherwise
+
+#### `public `[`midi_packet_length_t`](#group__midi__util_1gae29ff56aee2b430ffe53933b97e5e79e)` `[`midi_packet_length`](#group__midi__util_1gaa168b43af6ae9de0debce1625e4b8175)`(uint8_t status)` {#group__midi__util_1gaa168b43af6ae9de0debce1625e4b8175}
+
+Find the length of the packet associated with the status byte given.
+
+#### Parameters
+* `status` the status byte 
+
+#### Returns
+the length of the packet, will return UNDEFINED if the byte is not a status byte or if it is a sysex status byte
+