[RP] Adding support for a minimum output bar width

[hackme]

Adds barminwidth variable, which is responsible for the minimum width of the 
message bar area.

For example.

set barborder 3
set barminwidth 1440
set bargravity s
http://ozi-blog.ru/wp-content/uploads/2016/04/1-min.png

set barborder 3
set barminwidth 500
set bargravity w
http://ozi-blog.ru/wp-content/uploads/2016/04/2-min.png
http://ozi-blog.ru/wp-content/uploads/2016/04/4-min1.png

set barborder 3
set barminwidth 0
set bargravety ne
http://ozi-blog.ru/wp-content/uploads/2016/04/3-min.png

Diff file for ratpoison 1.4.8: http://ozi-blog.ru/ratpoison_1.4.8_2.patch

1-min.png
Description: PNG image

2-min.png
Description: PNG image

3-min.png
Description: PNG image

4-min.png
Description: PNG image