[TIMOB-588] deleting rows with headers via editable:true does not delete header

Deleting headers from rows via delete rowobj.header; also does not delete the header.

Possible fix. Now when there are 0 rows in a section, it is removed from the table (which also removes headers, footers, etc.) This may be undesirable because some applications may rely on sections existing even AFTER they are empty, for example, apps which list things alphabetically (which may start with 26 empty sections and just fill them up).

Uncommitted while searching for a better possible solution, and looking into whether or not the delete issue can be avoided.

(from [baf1546cf7eb200fbe2b98d5cc987a1c45e25cab]) Closes #588: Removes empty sections on row delete. http://github.com/appcelerator/titanium_mobile/commit/baf1546cf7eb200fbe2b98d5cc987a1c45e25cab"> http://github.com/appcelerator/titanium_mobile/commit/baf1546cf7eb2...

Calling delete row.header should be considered invalid. Instead, do that and then immediately update the row in the table using tableView.updateRow().

Note that now sections are deleted when empty, and so if a section a user wants to exist doesn't (for example, a section indexed by "B") they will need to re-create it when adding in some rows.