New list of projects filtered by angle to use in PieChart. Closes #432

Added simple method to SummaryReportView to obtain a list of projects for a minimum angle. Used on Ross and Joey.
fixes #432 
Imagine we have a week that have one project A of 20 hours and three projects (B,C,D) of 1 minute. 
In this case:

PieChartProjects = A ( has no sense to show thin slices with an angle less than 1dgr, not good for performance)
ListChartProjects = B, C, D ( is better to show the names, considering we're not showing it on piecharts )

This case is very common if you have projects with a big difference in duration ( test.account.2@toggl.com). There are a lot of projects ( 30 or more ) with 20 seconds of duration and together they don't represent enough to be showed.