(flexpath:regtests): added maya-noxml tests

passes with MPI method on laptop; segfaults with FLEXPATH method enabled
Merge branch 'v1.5.1' into mag-v1.5.1
(flexpath_tests:fixes+ref): changed the name of config.h to cfg.h, decrease the buffer for adios
(fxph:fix): readme update
Merge branch 'v1.5.1' into mag-v1.5.1
Merge branch 'v1.5.1' into mag-v1.5.1
(flx:bufix+refac); fixed a few macros as they could cause some errors, added parameters to one macro
(flx-reg-tests:new+refac): added new test testing appending mode,
refactoring of macros
Merge branch 'mag-v1.5.1' into v1.5.1