Filter connections per mode
changed filters approach to use buffer local vars
Improve the way to filter the installable docsets.

- Add a var with a list of ignored docsets.
- Use this var in helm-dash-available-docsets.
2 sets of docsets, global and buffer local
ensure connections are set
reformatted code and typofix
Merge pull request #18 from areina/add-ignored-docsets

Improve the way to filter the installable docsets.
use with-helm-current-buffer
checkdoc a bit
update-docset is the same as install
Merge pull request #16 from areina/filters

Filters
Determine the docset type.

- Add a function to get the docset type.
- Modify helm-dash-connections. Now it is a list with docset name,
- connection and docset type.
Add functions to build sql queries.
Doc for `helm-dash-available-docsets'.
Compose sql queries for dash and zdash formats.
Unify the ugly sql code in centralized var.
formatted lists correctly
attempt to make buffer local docsets work
Avoid multiline with sql statements.
ask to create docset dir