0.14.4-r2 patched it to fix for install its man pages' dir localtion. 0.14.5-r1 uses "make install" with MANDIR var, instead of it doesn't do patching. But it should be MANDIR=${D}/usr/share/man, not MANDIR=${D}/usr/share.
Created attachment 92265 [details, diff] a diff ebuild for x11-drivers/syynaptics-0.14.5-r1 to fix MANDIR For use MANDIR=${D}/usr/share/man, instead of MANDIR=${D}/usr/share.
Created attachment 92267 [details] equery's result x11-drivers/synaptics-0.14.5-r1 with this fixing. Its man pages should be installed like this, IMHO.
fixed with the commit of bug 144308 - sorry for the delay.