initialise all pmods used in a multiple timing definition, i.e. if a pmod is defined for a condition which does not occur in session 1, then ensure that empty pmods with respective names are created in pspm_get_timing
write a test in pspm_glm to check that this is working
Fixes #191 and fixes #195 .
Changes proposed in this pull request:
pspm_get_timingpspm_glmto check that this is working