Branch to work on filename handling without disturbing trunk.


[SVN r68345]
Use generic string for `__FILENAME__`.

Will hopefully a bit more consistent across platforms. Obviously proper
conversion to UTF-8 would be better.

[SVN r68391]
Change the way the filename is stored.

No longer stored in the iterator which means there's less messing around
with pointers and strings. Always stored as a fs::path which will help
with support for unicode. Also passed to outwarn and outerr as fs::path
so they can handle writing unicode filenames to the output.

[SVN r68392]
Use fs::path in more places.

[SVN r68393]
Use filesystem alias more consistently.

[SVN r68394]
Replace input_path with manual path conversion.

[SVN r68395]
Use a function to convert paths to and from utf-8.

This will eventually try to cope with unicode characters. Not sure if
it'll ever be truely cross platform.

[SVN r68396]
Windows support for unicode filenames.

[SVN r68397]
Fix class/struct warning.

[SVN r68398]
Move error and warning functions into input_path.

I'll rename it after merging with trunk. I'm just collecting all the
input and output functions together.

[SVN r68561]
Turn debug symbols off when testing quickbook.

Fixes an odd error with the Boost Build Visual C++ tool.

[SVN r68562]
Support for wide output streams on windows.

[SVN r68563]
Fix default output filename.

[SVN r68565]
Add ids to bridgeheads.

Prevents docbook from making up ever changing ids. It would be nice to
use the heading's anchor. But that causes docbook to complain that it
can't generate a title for the link.

[SVN r68595]
Nicer link break warnings.

[SVN r68609]
Check for portable paths in more places.

[SVN r68654]
Fix rooted path handling on windows.

Was using `!path.is_complete()` to check if a path is relative - this
doesn't work on windows since paths like `\a\b` and `c:foo` aren't
complete or absolute. So now use
`!path.has_root_directory && !path.has_root_name()` instead.

[SVN r68655]
Partial fix for portable path detection.

`portable_posix_name` is for checking names not paths. So instead just
warn if the path contains a `\` which is close enough. Should really be
using URLs. Maybe converting `\` to `/` (with a warning) for backwards
compatability.

[SVN r68656]
Get the quickbook test tool working from other directories.

[SVN r68875]
Count lines and columns from 1 in the quickbook iterator.

[SVN r68876]