title: qmake .pro file not parsed correctly to generate LD_LIBRARY_PATH
body: <p>I have been trying in the last days to understand how qmake works buy I'm stuck.
  I want a project with the following structure:</p>
  
  <p>root</p>
  
  <ul>
  <li>bin
  <ul>
  <li>testjson</li>
  </ul></li>
  <li>lib
  <ul>
  <li>libjson.so</li>
  </ul></li>
  <li>src
  <ul>
  <li>testjson.cpp</li>
  </ul></li>
  </ul>
  
  <p>All i wanted was to test the json library. I have created a new empty project in Qt Creator 2.3.0, and set up all the settings so the executable will run. Tested what I wanted and closed  the application.</p>
  
  <p>Later, when I opened Qt Creator again, I loaded the .pro file and surprise, when I try to run the project I get this message: "No executable specified." :| In this case I went to the project tab, and selected the executable manually but, as expected, when I tried to run it, I got this message "error while loading shared libraries: libjson.so: cannot open shared object file: No such file or directory". It was expected since the LD_LIBRARY_PATH is not set(it's like i'd run it from cli).</p>
  
  <p>It looks like the .pro file isn't parsed properly because the 1st time, on the project tab when I was selectig Run tab, I'd see a message : "Parsing .pro file", and then the running config would get filled, and greyed out, so it means that the LD_LIBRARY_PATH was added by Qt Creator after parsing the .pro file.</p>
  
  <p>Now my questing is: why was the .pro file parsed correctly 1st time?</p>
  
  <p>Here's the .pro file:</p>
  
  <pre><code>!include(../../common.pri){
      error(Couldn't find the common.pri file!)
  }
  
  TEMPLATE = app
  
  SOURCES += testjson.cpp
  CONFIG += console
  TARGET = testjson
  
  CONFIG(release, debug|release) {
      DESTDIR = $$BinaryDir/Release
  } else {
      DESTDIR = $$BinaryDir/Debug
  }
  
  LIBS += -L$$LibraryDir -ljson
  
  INCLUDEPATH += $$DefaultInclude
  DEPENDPATH += $$LibraryDir
  </code></pre>
  
  <p>PS: The solution is to manually add the LD_LIBRARY_PATH to the building environment, but I find this not the right way to do it.</p>