Various bugfixes (v1.2c)

# Misc changes
* Added dummy entry as 0th entry for the default MKWii definition data file
* Disabled debug mode (for users)
  * Refactored hiding Of THP Tab data into its own HideTHPData() function
* AssignSelPath_FBD() func
    * Added new optional param to define default directory to use if path is unset
    * Assigned new default directories for affected FolderBrowserDialog boxes in Options menu
        * FFMPEG Exe Root = "Program Files" folder
        * FFPlay WorkDir = "Downloads" folder
            * Handled via special Shell32 marshalled DLL call
            * Will use root directory instead if failure (due to running on legacy Windows etc.)
        * Data File Dir = Current Application path

# **Bugfixes**

## Issue #11
**THP Data Dir bugs:**
* Removed initialization of DataFile Dir path on application boot in Main_Load() func
* Set the DataFile Dir OpenFileDialog box to start at the application's current directory if path box is unset
* Force the user to define the DataFile Dir path every boot (or load it from settings INI file)
* Made setting the DataFile Dir path call InitTHPData function, in order to reload the data files
* Tweaked InitTHPData function
  * To use the DataFile Dir path for reading the data files
  * To clear and update the THP combo box contents
  * To set the THP combo box index to 0th, and force a SelectedIndexChanged event
    * Data files must now have a dummy entry defined as 0th entry
    * This event hides some THP tab data, and will force the user to select a valid THP to initialize displayed data
  * To hide the THP tab contents (call HideTHPData func) if failure due to caught errors

**TryParseErr_Single function culture bug:**
* Tweaked function to parse Single via Float number type and with Invariant culture
* Untested bugfix

## Issue #12: KeepInRange parsing bugs
* Disabled some Log_MsgBox function calls for less liberal error trapping

## Issue #13: Path Separator Char
* Work from previous commit
    * Made path separators use OS' Path.DirectorySeparatorChar instead of hardcoded backslash\  char
    * Made certain FFMPEG params (time trimming) use hardcoded backslash\ char

## Issue #14: Lingering File I/O
* Refactored all closing, disposing, and nulling of non-null StreamReaders/Writers blocks into  KillStream() func caws.
    * Overload for KillStream upon StreamWriter object can optionally delete file being written to
* Modified all Catch blocks made upon StreamReaders/Writers code to call KillStream() before error message box is shown

Author: Tamk1s

FileCDesc.txt

@@ -1,3 +1,4 @@
+n/a
 White box, determines highlighted track (1-5)
 n/a
 n/a

FileData.txt

@@ -1,3 +1,4 @@
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0;
 336,528,2,1,2,5,10,336,250,120,600,336,28,59.94,1,0,0,0;
 672,752,3,2,6,1,6,336,250,480,480,672,2,59.94,0,0,0,0;
 496,240,2,1,2,1,2,496,120,480,480,0,0,59.94,0,0,0,0;

FileDesc.txt

@@ -1,3 +1,4 @@
+n/a
 When a cup is highlighted in Battle Mode. Top=Wii, Bot=Retro. 5 courses per cup
 Video displayed when a track is highlighted for Battle Retro Cup. Subvideo in cell B3 is empty
 Video displayed when selecting a battle mode type. Top=Balloon Battle (Block Plaza), Bot=Coin Runners (Delfino Pier)

FileListing.txt

@@ -1,3 +1,4 @@
+=============================
 \battle\battle_cup_select.thp
 \battle\battle_retro.thp
 \battle\battle_select.thp