Support # in URLs

Also in this release, some keyboard navigation improvements have been
made to the input box used for searching.

Add QuitIfOneScreen and NoLineNumbers to embed API

Center search hits vertically

With this release, search hits will be centered on the page, rather than
appearing at the top or bottom as before. The point is to make them more
obvious.

Also in this release, iTerm2 now has working scroll + select out of the
box.

Backwards searching now scrolls sideways as needed

Also in this release:
- Fix selection not working in certain terminals
- Default line numbers to off when showing git output
- Support ^a and ^e to move to start and end of line

Make forward search find sideways matches

Before this release, if you had long lines and searched forward, hits to
the right of the screen weren't visible.

With this release, the search will scroll right to show search hits
that are off-screen to the right.

Also in this release:
* Show man page names in the status bar
* Make --quit-if-one-screen work with wrapping enabled
* Search text is now editable, cred to @masmu in PR #321

Match less' behavior with piped stdin

Piped stdin, no args: Just page stdin

Piped stdin with args: Page args, ignore stdin. Except if one arg is
"-", then stdin will be paged in place of that arg. If you provide
multiple "-", the first will be used and the others simply ignored.

If you pass "-" without piped stdin, it will be treated as a literal
filename.

Default tab size to 8 to be like less

In case somebody cares about the previous shorter default, this change
also adds a --tab-size flag to override the default tab size.

Fixes: #320

Pass all tests

Support opening multiple files

Switch between files using :n, :p or :x (next, previous, first).

Also in this release, keyboard shortcuts listed in the status bar are
now highlighted rather than quoted, saving room for the text and looking
a wee bit nicer.

Provide line highlighting in more cases

Before this release, a number of factors could prevent search hit line
highlighting from working.

With this release, most of those factors have been addressed, and line
highlighting should now work in most cases.