upgrading gwt bootstrap library
introducing new loading spinner panel
using new loaing spinner to visualize status, showing bootstrap alerts boxes to indicate errors
incremental processing the search result set to allow a better ui expierence
partial and incremental loading of single activity section
synch between filter and results panel
fixed #44
Merge branch 'bug/44-begin-work-dialog-twice' into dev
Merge branch 'feature/load-visualisation-quick-search' into dev
#45 introducing a new Ok Cancel Dialog similiar to JOptionpane in bootstrap modal style
fixed #45
Merge branch 'feature/45-fill-to-current-time-dialog' into dev
fixed #51 checking the workpackage periods

up to now, just the project periods were checked, which only prevents
from billing to expired projects. checking on the most recent
Workpackage period prevents from billing to expired workpackages and
from expired projects, since workpackes should not have a longer
expiration date the project they belong to.
Merge branch 'bug/51-billing-on-expired-workpackages' into dev
Merge branch 'dev' of github.com:cismet/project-tracker into dev