Updates and fixes for gumps package.

[AsYlum-]

Gumps package was a bit outdated. While looking into the client and working on updated Gump Studio tool. I've identified missing functions and mismatches against original client.

New additions and updates

• Added GFMasterGump - draws the gump as a sub-window of another gump.
• Added GFToggleUpperWordCase and GFToggleCroppedText - sticky parser flags, emit once per gump.
• Added GFECHandleInput - only the Enhanced Client acts on it.
• Added GFEndRadioGroup - closes a group opened by GFSetRadioGroup.
• Added GFPicInPic - draws a cropped region of a gump graphic. Needs a High Seas or newer client.
• Added GFTilePicAsGumpPic - draws an art tile in a gump-art slot. link_id is one-based.
• Added XGFAddToLayout - writes a raw layout line, for elements with no GF* wrapper yet. It was already in the header's private function list but had never been written.
• GFGumpPic now emits 'GumpPicHued' rather than the 'hue=' attribute, and takes a 'partial' parameter selecting 'GumpPicPHued'. Dyeable cloth and armour need partial := 1.

Fixes

• Fixed GFDisposable testing CloseLoc where it meant DisposeLoc.
• Fixed GFResizePic and GFPicTiled falling back to base.width when passed a height of 0.
• Fixed GFTextCrop appending its text to the data array twice.
• Fixed GFAddButton and GFAddImageTileButton writing six of the Button command's seven slots for a page button. In GFAddImageTileButton the tile parameters follow, so the client read tilepic_id as the return value and every tile parameter one place too early.
• Fixed GFAddHTMLLocalized guarding a branch with SizeOf(customstring) == 0. SizeOf() is memory used, not length, so it is never 0 and XMFHTMLGumpColor was unreachable - a hued cliloc with no argument went out as XmfHtmlTok with an empty '@@' block.
• Fixed GFTooltip emitting a malformed line: no space before the argument block, an empty '@@' for argument-less clilocs, and a trailing stray apostrophe.