Branch development version of quickbook.
Update quickbook version number.
Create entry for 1.5 in the change log.

Starting it of with some of the changes that have been made to quickbook
since 1.4 - considering the first 1.4 release as the proper 1.4 release.
Wrap the template info in a struct.

So that I can add extra scoping info.
Add a couple of tests for quickbook 1.4 behaviour to try to preserve it.
Implement static/lexical scoping for 1.5. Refs #2034.
Move all the syntax highlighting code into a single class.
Move the code actions a bit later in actions.hpp so they can use 'plain_char_action'.
Teletype source mode. Refs #1202.
Make sure that a template expansion ends with a ']'.

{{{
[template foo 1]
[fool]
}}}

was generating `1[fool]` - the template would be expanded but then when it
didn't match the `]` it would fail and just get copied to the output. This
change checks for `]` before expanding the template. So it now generates
`[fool]` which is an improvement.

I'm not including a version switch as I see this as a plain bug fix - I can't
imagine this change ever being anything but beneficial.
In quickbook 1.5 don't mix '..' and whitespace seperators for template arguments. Refs #1174
I got a bit confused by this comment, so try to make it clearer.
Put the quickbook version numbers in a single header, along with convenience
functions for using them in spirit grammars.
Ignore spaces after 'section:' for quickbook 1.5+ Refs #2712

And warn when section id is empty after colon.
Introduce temporary id variable.
Table ids. Refs #1194.
Separate out the current version of the template argument parser, as I want to create a new one for 1.5
Don't use seperators that are in brackets, or are escaped. Refs #2036.
Add missing table tests.
Support image attributes. Refs #1157.