BL-815: Improve previews of templates

- locate xmatter CSS correctly
- hide images with no src
Attach log file instead of appending it to description

If we don't have a log file we append the line "No log available" to
the description, otherwise we attach the log file to the jira issue.
Don't show reporter dialog on taskbar

On Linux the dialog shows up as question mark in the task bar, so we
either have to set a proper icon or not show it which is what I
decided to do.
Merge branch 'tryAgainUpload'
Merge pull request #190 from ermshiperete/LogAsAttachment

 Attach log file instead of appending it to description
Fix failing unit tests on Linux builds on Jenkins

The unit tests that access S3 fail on Jenkins because the build
agent is behind a proxy.The Amazon SDK classes don't make use of the
http_proxy environment variables, causing the tests to fail.

This change retrieves the proxy settings from the http_proxy or
HTTP_PROXY environment variables and sets the corresponding
properties for the S3 client.
Fix case of output directories
Ignore failing tests on Linux
Add Setup fixture that runs the Geckofx initialization code once
Fix of requires-paragraph detection
Clean up splash screen a bit
Cleanup: Add missing TestFixture attributes to tests
Merge pull request #198 from ermshiperete/proxy

Make unit tests greenbar on Linux
Ignore failing unit test on Windows

Environment variables on Windows are not case-sensitive which makes
this test pointless for Windows.