I just tried to 'make' the Linux QT version and thought everything was going well until it terminated with this error:

g++ -c -fpermissive -fstack-protector-all --param ssp-buffer-size=1 -O2 -D_REENTRANT -fdiagnostics-show-option -Wall -Wextra -Wno-ignored-qualifiers -Wformat -Wformat-security -Wno-unused-parameter -Wstack-protector -fPIE -DQT_GUI -DBOOST_THREAD_USE_LIB -DBOOST_SPIRIT_THREADSAFE -DQT_DISABLE_DEPRECATED_BEFORE=0 -DUSE_UPNP=1 -DSTATICLIB -DUSE_IPV6=1 -DHAVE_BUILD_INFO -DLINUX -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I/usr/lib/x86_64-linux-gnu/qt5/mkspecs/linux-g++-64 -Isrc -Isrc/json -Isrc/qt -Isrc/leveldb/include -Isrc/leveldb/helpers -I/usr/include/qt5 -I/usr/include/qt5/QtWidgets -I/usr/include/qt5/QtGui -I/usr/include/qt5/QtCore -Ibuild -Ibuild -o build/net.o src/net.cpp
src/net.cpp:19:32: fatal error: miniupnpc/miniwget.h: No such file or directory
 #include
                                ^
compilation terminated.
make: *** [build/net.o] Error 1

I've done a little searching for a fix but didn't find anything useful (to me anyway - I'm not a coder, just a reasonably proficient user). I don't know enough to know what the error fully means or where to try and fix it. Any help getting the GUI wallet in Linux installed gratefully received!
I'm using Linux Mint 17 64bit, I cloned the github files from here - https://github.com/dennemann/britcoin, anything else I should tell you about my system?