User should be able to distinguish between Qt OSS and Qt Commercial

Assumption: qmake is the fundamental command to run a Qt project. (we should consider a similar approach for qbs)

Problem: User has installed multiple versions of Qt, some under OSS and some under Enterprise license, and cannot distinguish which versions of Qt are under which license. User needs to ensure that certain project(s) is(are) only compiled against Enterprise Qt

Proposal: qmake identifies itself as "OpenSource" or "Commercial" (or "Evaluation").

(1) This information can be shown in the "Kit" information section of Qt Creator and thereby making it easier for the user to compile against the correct license of Qt. 

(2) If user is building from command line, a command such as "qmake -edition" would help the user identify the correct license of Qt