Implemented ts_api:get_user/2, ts_api:put_user/1, and ts_api:post_user/1.

Created a utility function for OK results, ts_api:make_json_200/2
Created ts_common:new/1 and ts_common:update/1 to generalize record creation and update.
Refactored ts_timeline:new/1 and ts_timeline:update/1 to use the ts_common functions.
Implemented ts_json:record_to_ejson/1 and ts_json:ejson_to_record/1 for ts_user records.
Implemented ts_user module.

src/ts_entry.erl

@@ -42,7 +42,7 @@ when is_integer(Start) and is_integer(Length) ->
         MatchHead = #ts_entry{ref = {Username, Timeline, '_'}, _='_'},
 
         % select all records that match
-        mnesia:select(ts_entry, [{MatchHead, [], ['$_']}]
+        mnesia:select(ts_entry, [{MatchHead, [], ['$_']}])
     end),
 
     % sort
@@ -69,7 +69,7 @@ list({Username, Timeline}, StartDateTime, EndDateTime, OrderFun) ->
         EndGuard = {'<', '$1', EndSeconds},
 
         mnesia:select(ts_entry, [{MatchHead, [StartGuard, EndGuard], ['$_']}])
-    end,
+    end),
 
     % sort
     lists:sort(OrderFun, Entries).