Exclude libxputty files from make install

[fpesari]

Hello,

in v0.7 make install also installs files from libxputty (in /usr/include and /usr/lib and /usr/share/pkgconfig). However, if libxputty is statically linked to XUiDesigner, they should not be installed to the user's system. Thanks!

[brummer10]

Hi
While that is true, we need to have libxputty installed in order to compile and run the test build UI. That's why libxputty was installed by XUiDesigner.