Add an option to indent with tabs instead of spaces

I can't see an easy way to get this into the shortcuts and have no run
the unit tests. Please excuse my python inabilities.
Remove the button synonym

Remove button as a synonym for an input with type button. Button is a
perfectly good element in it's own right.
Turn the spaces in shortcuts into tabs

This will probably break the unit test and is not adjustable by
options. Not recommended.
/env python -> /env python2

On Archlinux python is linked to python3.
Do not add normal mode mappings for Vim.

Closes #35
Improve mapping for Vim, using <Plug> maps>

Add redirection through <Plug>SparkupExecute and <Plug>SparkupNext and
check if mappings are defined for them before assigning default maps.
Fix doc installation in "vim" Makefile task.

Copy README to 'doc' subdirectory and mark the header with asterisks.
The latter appears to be required for `:helptags` to pick it up.
Use `inoremap` for calling Sparkup{,Next}().

This will make the mapping work properly with e.g.
`noremap : .`.

See https://github.com/rstacruz/sparkup/pull/40#issuecomment-1202903
Use `return` instead of `finish` in a function
Use full path for s:sparkup

When determining `s:sparkup` the whole path should get used.
`findfile()` might return a relative path, so we use `fnamemodify(..,
':p')` to transform it into an absolute path.
Mention sparkup.py besides sparkup in the error message
Unset s:sparkup in case of error

Besides allowing for a re-detection on next invocation, it will prevent
and error from trying to execute an empty command.
/env python -> /env python2

On Archlinux python is linked to python3.
Merge pull request #72 from Profpatsch/master

/env python -> /env python2
Use `imap` when mapping to `<Plug>*`

Fixes  rstacruz/sparkup#74
Merge pull request #75 from blueyed/master

Use `imap` when mapping to `<Plug>*`
Retain inner } braces, useful for templates

When div{{{title}}} is mapped it will become <div>{{title}}</div>
Execute html mappings for Django templates
Merge pull request #77 from maurizi/master

Some support for Django templates
Add HTML5 self closing tag support