[KDev4] Project parsing and loading

[dukju ahn]

Why ImportProjectJob which is called in KDevelop::Project::open()
parses _every_ contents of full project tree at openning time?
IMHO, it is waste because not all user doesn't develop every
part of one project. For example, I don't go over languages,
sublime, editor etc.

It would be more efficient to parse just toplevel items, and
only when the user clicks dome directory, we can  just parse
that dir. It tooks 3 seconds to open kdepimlibs in custommake
manager, and I even gave up to open kdelibs.

Also, was there any reason for ImportProjectJob not to use
QThread internally??