[patch] more sesponsive file search dialog

[Roland Illig]

Jindrich Makovicka wrote:
> Hello,
> 
> Currently, during the file content search, no events are checked, which 
> is very annoying when mc hits a big file and the UI freezes. This patch 
> adds event checks to the code for searching the file contents.
> After applying, the Find File dialog works all the time during the 
> search, so the searching can be stopped or suspended&resumed even in the 
> middle of a file. For suspend&resume, the code is modified to make sure 
> the search will continue where it previously ended.
> 
> This is about third time I try to submit this patch and hope it could be 
> finally included in some form.

Committed.

Roland