Add investment under group or no group to list

Fixes #17

Adding a symbol alone or under a group. The actual DOM call is $.after, which
is correct for groups but probably not for alone ones. The tests must be still
working due to some issue with the findSymbol function selectors.

TODO:
- Change code so alone symbols get prepending to list rather then aftered.

Other:
- Modifications to how group data is passed around when adding.