Improve implementation class search

[Matthias Schoettle]

When importing an implementation class, searching for the class is very cumbersome

• when typing the fully qualified the search result does not produce the expected result
• searching for, for example, "ArrayList", "List", "Set" shows a lot of irrelevant classes first
• typing into the search field quickly starts lagging because it takes a lot of time to visualize the intermediary result

[Arthur Le Saint]

Resolves #508: Implementation class search improvement

• A lot has been remove, it's now a simpler search.
• setElementsOrder(Comparator) now just change the Comparator to order the elements. It used to refresh the gui list (which should not be in this method).

Note: when you type 'java', it does not shows the possibilities yet (too much)

→ <<cset 1e7ffc6d556c>>

[Matthias Schoettle]

References #508: Removes unused Apache Commons Lang library from build path and build script.

→ <<cset 1f969f1c905b>>

[Arthur Le Saint]

References #508: Search is not case sensitive anymore

→ <<cset d4b18f5afc93>>

[Arthur Le Saint]

Merged in Issues/508-Improve-implementation-class-search (pull request #132)

Resolves #508: Implementation class search improvement

Approved-by: Matthias Schoettle [e-mail]

→ <<cset 74d029d921e1>>