Add vim-repeat support

Commands like `glip=` can be repeated with the dot command to align the
next paragraph.
Merge pull request #6 from wellle/repeat

Add vim-repeat support
Merge pull request #5 from wellle/master

Match alignment characters literally
Link to GitHub issues in TODO section of doc
Add ~ to list of chars to be interpreted literally

An amendment to pull request #5
Support characterwise and blockwise motions

Closes #2
Closes #4
Clean up unused variables
Fix blockwise end detection
Add support for alignment by patterns

Closes #7
Fix visual mappings (closes #8)
Describe pattern alignment in README
Update issues and todo in doc
Update website in doc