- Use pristine upstream tarball

- change autogen.sh call to autoreconf

- convert asciidoc files to man pages

- update to 1.2.1
* Incompatibilities:
- Move manual and man pages to doc/ directory and rename AsciiDoc files
to have .asciidoc as the extension to make them render on GitHub.
* Improvements:
- Show blob sizes in the tree view either as bytes or using binary unit
prefixes. Example: `set show-file-size = units`. (GH #163)
- Reduce main view memory usage and startup time, especially when revision
graph rendering is disabled. (GH #160)
* Bug fixes:
- Fix submodule-related setup to check for non-zero return value from
setenv(). (GH #188)