pidgin/pidgin

Replace the manual browser opening code with gtk_show_uri_on_window

Remove the browser preference page.

replace the manual open uri code with gtk_show_uri_on_window

Testing Done:
Compiles, preference window functions properly, however talkatu doesn't handle links correctly so I couldn't test from messages or `help -> about`, but `help -> online help` worked just fine.

Reviewed at https://reviews.imfreedom.org/r/59/
/* XPM */
static char * arrow_down_xpm[] = {
"13 16 30 1",
" c None",
". c #5C3566",
"+ c #D3BBD1",
"@ c #D5BDD2",
"# c #D5BED3",
"$ c #CFB5CC",
"% c #C9ABC6",
"& c #623C6C",
"* c #D4BDD2",
"= c #C2A0BE",
"- c #613A6A",
"; c #BC9FBB",
"> c #C8AAC5",
", c #BB95B7",
"' c #623B6B",
") c #BEA2BD",
"! c #B48BB0",
"~ c #B58BB0",
"{ c #BDA1BC",
"] c #BEA2BE",
"^ c #C5A5C2",
"/ c #AE81A9",
"( c #C7A8C3",
"_ c #BFA3BE",
": c #D0B6CD",
"< c #BB9FBB",
"[ c #623C6B",
"} c #A787A8",
"| c #603A6A",
"1 c #5E3667",
" ..... ",
" .+@+. ",
" .@#@. ",
" .@#@. ",
" .@#@. ",
" .@#@. ",
" .@#@. ",
" .@$@. ",
" .@%@. ",
"....&*=*&....",
" -;**>,>**;- ",
" ')%!!~%{- ",
" ']^/(;- ",
" '_:<- ",
" [}| ",
" 1 "};