Improve usability of "ignore issues" feature

[sebastiansirch]

Currently, ignored issues can only be collected via the diagram. It would be handy to have the same button in the table as well as a download-button at the buttom.

We could even further enhance this feature by showing a list of collected issues with the ability to remove specific issues from the collection. (Currently, it is not possible to remove an issue after it has been added once).

[sebastiansirch]

Another aspect: Lines in the ignoredIssues.txt file are cut off after 32 chars which makes this file very hard to read. I don't see a reason why we need to shorten the lines that heavily.

Example where it is hard to guess the meaning...

#Element mit ID 'serviceTask_d..
123somehashvalues456
#Element mit ID 'serviceTask_a..
123anotherhashvalues456

[fkoehne]

I made separate issue out of this one: #74.

[sdibernardo]

I agree on the usability of having a button in the table to add issues to the whitelist. Will keep this in mind. Thanks for the feedback

[sdibernardo]

Added some buttons and functionality. Please have a look. Im open for feedback :)
@sebastiansirch
@fkoehne
@cl-a-us