Make SW UAC friendly

* I moved every file that can have modifications to "X:\Users\[User Name]\AppData\Roaming\Subtitle Workshop" (Vista+) or "X:\Documents and Settings\[User Name]\Application Data\Subtitle Workshop" (XP-), meaning:
    * Custom Formats Examples\*
    * CustomFormats\*
    * Langs\*
    * OCRScripts\*
    * PascalScripts\*
    * FPS.ini
    * Output.ini
    * shortcuts.key
    * SubtitleWorkshop.ini

* Edited the installer to reflect the previous change, added UAC elevation to the installer, fixed a few bugs in the installer code.
    * The "Help" folder would be created in Start Menu even if you didn't select any manual during the install
    * The shortcuts for the manuals had the wrong path ($INSTDIR\Manual instead of $INSTDIR\Help) and had invalid values for icons
    * The working dir for executables' shortcuts would be set to the last value used for SetOutPath, this could cause some problems, so I made sure to set the right value before creating any shortcuts

* I tried to add a few more name/dir constants and make sure the existing ones were used across the entire code.

* For portable builds, it is now necessary to define PORTABLE in the compiler settings to make SW fall back to the previous behavior of creating and loading files from the same directory as the executable.
Add portable build support for batch files
Added local copy of the UAC plug-in for NSIS v0.2.4