support c++17

Mnt/c++17

See merge request !32

CI: Don't run CI tests on tags or master branch

See merge request !31

Mnt/fsldevdir rpath

See merge request !30

Mnt/post 606

See merge request !29

RF: Better way of adding -install_name option

See merge request !28

evaluated against $@="", so was matching all targets

MNT: rpath

See merge request !27

specified in environment. This is to support local development, so that
exes can be executed from $FSLDIR/src/<project>/<exe> and that libs in
$FSLDIR/src/<project>/ will take precedence over those in $FSLDIR/lib/

default since ~2010. Explicitly set rpath to pwd, pwd/../lib, and
$FSLDIR/lib. Set install name for shared libs on macOS so that executables
will refer to them via rpath.

These last two changes are explicitly performed by conda build, but are needed
for stand-alone/development compilation

MNT: note about compute capabilities

See merge request !26

Mnt/cuda compute capabilities

See merge request !25

TEST: Make sure wrapper can be created for "<command>_gui" if the source command exists

See merge request !24

command exists

BF: install errors if it gets given a dir name

See merge request !23