Minor correction for BUILD.txt

BUILD.txt

@@ -1,5 +1,5 @@
 Doxygen uses cmake (http://www.cmake.org/) to build executables for various platforms.
-It's required at least cmake version 3.0.
+It's required at least cmake version 2.8.12
 
 The first step is to create a build directory where the output should be stored.
 Doxygen can be fully build outside of the source tree.
@@ -34,6 +34,7 @@ Doxygen's cmake configuration provides a number of options:
 - use_libclang    Add support for libclang parsing.
 - win_static      Link with /MT in stead of /MD on windows.
 - english_only    Only compile in support for the English language.
+- force_qt4       Forces doxywizard to build using Qt4 even if Qt5 is installed
 
 An option can be turned on, by adding -D<option>=ON as a command line option, this can be
 done when generating the initial build files, but also afterwards, i.e. to enable building