make the startup script work with directories containing spaces.

Thanks to "catanzag" on the labs blog.

bin/qtcreator

 #!/bin/sh
 
-bindir=$(dirname $(readlink -nf $0))
+bindir=$(dirname "$(readlink -nf $0)")
 if test "$(uname -m)" = "x86_64" ; then
-    libdir=$(cd ${bindir}/../lib64 ; pwd)
+    libdir=$(cd "${bindir}/../lib64" ; pwd)
 else
-    libdir=$(cd ${bindir}/../lib ; pwd)
+    libdir=$(cd "${bindir}/../lib" ; pwd)
 fi
 LD_LIBRARY_PATH="${libdir}/qtcreator:${LD_LIBRARY_PATH}" exec "${bindir}/qtcreator.bin" ${1+"$@"}