- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Purge some useless mergeinfo.

Instead of only being able to compare two terminal definitions, now
also be able to print information about...

- length of the terminal capabilties
- dump of one terminal definition
- relationship overview for a terminal definition

Rename since it has will have more capabilities than just comparing of
two termcap entries.

Tool to compare two (roughly similar) termcap entries (like rxvt-mono
and rxvt-unicode) so see which fields should don't need to be copied
if the :tc=xxx: option is used.