Update build instructions for commercial licensees

Add build instructions for commercial licensees as well so that the
same README covers both opensource and enterprise users.

This removes the need having separate README file for commercial users.

Change-Id: Ibd3012b428c6fa85f47c1c459d8029ebfce92046
Reviewed-by: Jani Heikkinen <jani.heikkinen@theqtcompany.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

README

@@ -39,11 +39,24 @@ HOW TO BUILD QT5
      The "bin" folder of the ICU installation should be appended to the PATH
      environment variable in order to for the DLLs to be found at run-time.
 
+   Licensing:
+   ----------
+
+    Opensource users:
+
+        <source_package> = qt-everywhere-opensource-src-<version>
+        <license>        = -opensource
+
+    Commercial users:
+
+        <source_package> = qt-everywhere-enterprise-src-<version>
+        <license>        = -commercial
+
    Linux, Mac:
    -----------
 
-     cd <path>/qt-everywhere-opensource-src-<version>
-     ./configure -prefix $PWD/qtbase -opensource -nomake tests
+     cd <path>/<source_package>
+     ./configure -prefix $PWD/qtbase <license> -nomake tests
      make -j 4
 
    Windows:
@@ -55,8 +68,8 @@ HOW TO BUILD QT5
      * Python version 2.7 or later  [http://www.activestate.com/activepython/]
      * Ruby version 1.9.3 or later  [http://rubyinstaller.org/]
 
-     cd <path>\qt-everywhere-opensource-src-<version>
-     configure -prefix %CD%\qtbase -opensource -nomake tests
+     cd <path>\<source_package>
+     configure -prefix %CD%\qtbase <license> -nomake tests
      nmake // jom // mingw32-make
 
      To accelerate the bootstrap of qmake with MSVC, it may be useful to pass
@@ -81,13 +94,13 @@ HOW TO BUILD QT5
  Example for a release build:
  (adjust the `-jN' parameter as appropriate for your system)
 
-   ./configure -prefix $PWD/qtbase -opensource
+   ./configure -prefix $PWD/qtbase <license>
    make -j4
 
  Example for a developer build:
  (enables more autotests, builds debug version of libraries, ...)
 
-   ./configure -developer-build -opensource
+   ./configure -developer-build <license>
    make -j4
 
  See output of `./configure -help' for documentation on various options to
@@ -100,7 +113,7 @@ HOW TO BUILD QT5
  a `make module-<foo>'.  For example, to build only qtscript and qtwebkit,
  and the modules they depend on:
 
-   ./configure -prefix $PWD/qtbase -opensource
+   ./configure -prefix $PWD/qtbase <license>
    make -j4 module-qtscript module-qtwebkit
 
  This can save a lot of time if you are only interested in a subset of Qt5.