Include config.h in every c file and include it first.
Another history processing improvement.

Don't translate file lines into history or bookmarks structs, if we have
enough unique items in the processed list (history max items). So it's not
necessary to convert the lines and to remove them in a second step from the
list.
Don't put 'about:*' uri into history.
Removed vimb.1.txt to process manpage direct for install target.