Add Peter Provost's PowerShell plugin for Vim

See headers of any of the committed files.

vim/ftdetect/ps1.vim

@@ -0,0 +1,27 @@
+" Vim filetype plugin file
+" Language:	Windows PowerShell
+" Maintainer:	Peter Provost <peter@provost.org>
+" Version: 1.0
+"
+" $LastChangedDate $
+" $Rev $
+
+" Only do this when not done yet for this buffer
+if exists("b:did_ftplugin") | finish | endif
+
+" Don't load another plug-in for this buffer
+let b:did_ftplugin = 1
+
+setlocal tw=0
+setlocal commentstring=#%s
+setlocal formatoptions=tcqro
+
+" Change the browse dialog on Win32 to show mainly PowerShell-related files
+if has("gui_win32")
+	let b:browsefilter = "PowerShell Files (*.ps1)\t*.ps1\n" .
+		\ "All Files (*.*)\t*.*\n"
+endif
+
+" Undo the stuff we changed
+let b:undo_ftplugin = "setlocal tw< cms< fo<" .
+	\ " | unlet! b:browsefilter"