New Report - timesheet

- Added new timesheet report framework
- Began adding logic pseudo-code
- Added some documentation

src/parse.cpp

@@ -116,6 +116,7 @@ static const char* attributes[] =
   "",
 };
 
+// Alphabetical please.
 static const char* commands[] =
 {
   "active",
@@ -141,6 +142,7 @@ static const char* commands[] =
   "stop",
   "summary",
   "tags",
+  "timesheet",
   "undelete",
   "undo",
   "version",