Added UUIDs to timestamps, refactored the build process

* Added UUIDs to `ts_entry` records. Updated `ts_json:construct_record` to
  respond to `uuid` member properties if present. UUIDs are not required by the
  strict parsing functions in `ts_json` because the client will make a request
  with no UUID if it is a purely new timestamp. IN fact, this is the normal
  case. The UUID is only present when another tool is syncing its copy of this
  timeline wand adding entries that it has created and assigned UUIDs to.
* `ts_entry:new` will create a UUID for a new entry if it does not already have
  one.
* Restructured the build process to put all build artifacts into a dedicated
  `build` subdirectory, instead of mising them in an amongst the source code.
* Added the `uuid` module to the project. It can be found at

      https://gitorious.org/avtobiff/erlang-uuid

* Rewrote asset URLs to use relative paths instead of absolute paths. Relative
  paths are correct in this case, becuase assets always live alongside the HTML
  pages. This change was needed to accomodate the new organization of the JDB
  Labs dev environment, where all projects live under subdirectories of the
  same virtual server instead of subdomains.
* Tweaked the timestamp entry fields in the web UI to save when the field is
  blurred, not just when <Enter> or <Ctrl>-<Enter> is pressed (though those
  still work).

src/ts_db_records.hrl

@@ -28,6 +28,8 @@
 
 -record(ts_entry, {
     ref,        % {username, timelineid, entryid}
+    uuid,       % UUID for this entry across all implementations and copies of
+                % this timeline.
     timestamp,  % gregorian seconds
     mark,       % String description of entry
     notes       % String with further notes about the entry

src/ts_entry.erl

@@ -24,7 +24,11 @@ new(ER = #ts_entry{}, ExtData) when is_list(ExtData) ->
 do_new(ER = #ts_entry{}) ->
         {Username, TimelineId, _} = ER#ts_entry.ref,
         NextId = id_counter:next_counter(ts_entry_id),
-        NewRow = ER#ts_entry{ref = {Username, TimelineId, NextId}},
+        RowWithRef = ER#ts_entry{ref = {Username, TimelineId, NextId}},
+        NewRow = case RowWithRef#ts_entry.uuid of
+            undefined -> RowWithRef#ts_entry{uuid = uuid:uuid4()};
+            _ -> RowWithRef
+        end,
         ok = mnesia:write(NewRow),
         NewRow.
 

src/ts_json.erl

@@ -46,6 +46,7 @@ record_to_ejson(Record=#ts_timeline{}, ExtData) ->
 %  "id":            "1",
 %   "timestamp":    "2011-01-01T14:01.000Z",
 %   "mark":         "Workout.",
+%   "uuid":         "98ed5198-0c98-47c7-96c9-52b57a2c605a",
 %   "notes":        "First workout after a long break."}
 
 record_to_ejson(Record=#ts_entry{}, ExtData) ->
@@ -62,6 +63,7 @@ record_to_ejson(Record=#ts_entry{}, ExtData) ->
         {id, EntryId},
         {timestamp, encode_datetime(DateTime)},
         {mark, Record#ts_entry.mark},
+        {uuid, uuid:to_string(Record#ts_entry.uuid)},
         {notes, Record#ts_entry.notes}] ++
         lists:map(fun ext_data_to_ejson/1, ExtData)}.
 
@@ -171,6 +173,7 @@ construct_record(Entry=#ts_entry{}, [{Key, Value}|Fields], ExtData) ->
                 decode_datetime(Value))},
             Fields, ExtData);
         mark -> construct_record(Entry#ts_entry{mark=Value}, Fields, ExtData);
+        uuid -> construct_record(Entry#ts_entry{uuid=uuid:to_binary(Value)}, Fields, ExtData);
         notes -> construct_record(Entry#ts_entry{notes=Value}, Fields, ExtData);
         _Other ->
             ExtDataProp = ejson_to_ext_data({Key, Value}),