Unimplemented DMF control attributes

[ike709]

See http://www.byond.com/docs/ref/skinparams.html#allparamstable

• is-checked (is-checked and group for menus #1462)
• can-check (is-checked and group for menus #1462)
• group (is-checked and group for menus #1462)
• is-transparent
• drop-zone
• title
• titlebar
• can-close
• can-minimize
• can-resize
• is-maximized
• image
• image-mode
• stretch
• keep-aspect
• transparent-color
• alpha
• splitter (Several interface fixes #1408)
• multi-line
• is-flat
• pushbutton
• icon-size
• text-mode
• on-show (Implement on-show and on-hide for map controls, plus winset parsing fixes #1450)
• on-hide (Implement on-show and on-hide for map controls, plus winset parsing fixes #1450)
• link-color
• visited-color
• cell-span
• style
• enable-http-images
• focus
• max-lines
• flash
• no-command (Fix some DMF issues #2336)
• map-to
• show-history
• tab-background-color
• tab-font-family
• tab-font-size
• tab-font-style
• tab-text-color
• tabs
• show-url
• use-title
• highlight-color
• allow-html

[wixoaGit]

All possible control parameters were added as valid keywords in 6a03889. They currently don't do anything, and instead just print warnings to the console.

[amylizzle]

#1462 does is-checked, can-check, group
#1450 does on-show and on-hide

[amylizzle]

#1757 defines all the properties and their defaults but does not implement behaviour

[PowerfulBacon]

#2618 adds support for titlebar