[Pidgin] #3267: Replace !PluginPref API with Request API

[Pidgin]

#3267: Replace !PluginPref API with Request API
------------------------+---------------------------------------------------
 Reporter:  rekkanoryo  |       Owner:  sadrul
     Type:  patch       |      Status:  new   
 Priority:  minor       |   Milestone:  3.0.0 
Component:  libpurple   |     Version:  2.2.0 
 Keywords:              |     Pending:  0     
------------------------+---------------------------------------------------
 According to a comment on the AfterTwoOhOh wiki page:

 There's some amount of duplication between the !PluginPref API and the
 Request API. This should be fixed. Finch currently converts a !PluginPref
 frame into a !RequestFields (gntplugin.c:process_pref_frame), which allows
 it to reuse the Request API's UI. Each name and label of a !PluginPref
 maps one-to-one with a !RequestField. However, a !PluginPref can impose
 some restrictions on a value (eg. min/max values for an integer
 preference), which a !RequestField still can't do. So some additions to
 the Request api will be necessary.

 ----

 If we really want to do this, I would suggest that we add a _with_limits
 function to each request field type that needs it.  This would allow us to
 make a transition in 2.x by making !PluginPref be a wrapper for Request,
 and then at 3.0.0 we can kill !PluginPref and rename the _with_limits
 functions to replace their predecessors.

-- 
Ticket URL: <http://developer.pidgin.im/ticket/3267>
Pidgin <http://pidgin.im>
Pidgin