Added Version Checking

New Update form is displayed when the "Updated" field on DFFD is newer
than the locally stored version field in LNPWin.txt *AND* todays date is
newer than the CheckAgain date stored in LNPWin.txt.

Update form gives you the option of Updating now (closes the application
and opens the DFFD page in your default browser), Remind later (With
options for: Next Run, 1 day, 3 days, 7 days, 1 week, 1 Month...which is
then written to LNPWin.txt), or not to Update at all, which just closes
the form.
Fixed date format

Hopefully clearing up any international date problem!
Hopefully fixed versioning!

Changed CheckAgain date formatting to be yyyy-MM-dd.  Read from the dffd
versioning page on first run and write that to LNPWin.txt.

Hopefully no more invalid format exceptions
Added checking directory name for version

Defaults to checking directory name for version on first run.  If there
is no version information matching "XX_YY rZ" (has to have all of the
parts) in the executing directory name on first run, then it will check
DFFD for the current version.

Either method then writes the current version to LNPWin.txt
Fixing LNPWin.txt

Forgot to change it back to the 0 default!
Merge pull request #16 from Keirathi/master

Hopefully versioning is fully functional now! closes #9