Added more constructors 
 - Go to DARIAH defaults with this(aIdp, aUsername, aPassword)
 - Extend DARIAH defaults with explicit proxy (appears to be required
for Glassfish)
 - Extend client completely by making HttpPostProcessor() optional
Update ShibHttpClient.java

Tweaked the JavaDoc comments for the constructors
Update ShibHttpClient.java

Missed a dodgy JavaDoc.
General cleanup
 - Replaced private constants with their HttpRequest equivalents
 - Replaced tabs with spaces again to match the rest of the code
Merge remote-tracking branch 'origin/master'
Split out three portions that could be methods.
Spelling mistake
Merge pull request #5 from spaetow/master

Some general improvements to ShibHttpClient