Add the paging to the log and diff commands.
Allow configuring the pager in the svnwrap config.
Colorize log output.
Remove trailing whitespace.
- Avoid bare "less" command in case user's "LESS" variable lacks "-R".

- Allow arguments for pager configuration.

- Default to "less -FRX" (following Git's lead).
Release version 0.6.0.

- New feature: Use a pager when the output won't fit on one screen.
  (Implementation by John Szakmeister.)

- New feature: Colorize "svn log" output.
  (Implementation by John Szakmeister.)
Use the shell when running the pager command.

This allows things like "diff-highlight | less" to be used as the pager
command.
Version 0.6.1: Use a shell for pager.