v0.7.3: Link sub & name detection fixes

- If your config file lists files that don't exist in the filesystem and
don't have titles explicitly specified, Dactyl now prints a warning
instead of exiting immediately. You can successfully build targets that
include all their files even if your config file lists other targets
that have missing files.
- Link substitution now works properly in Markdown (--md) mode, including
regular-expression based link substitutions.

Author: mDuo13

dactyl/version.py

@@ -1 +1 @@
-__version__ = '0.7.3-a3'
+__version__ = '0.7.3'