#1816: Adios autotools.  #1814: "make install" now installs header files.  #1815: "make vapi" and "make 
install-vapi" will create and install gexiv2.vapi.  This is a separate task because (a) gexiv2 must be installed 
for the VAPI generation tools to work and (b) not all gexiv2 developers may have a need for the VAPI file.