Fix #296: SYNCHDMLC not available in BEAMnrc gui
Fix #296: SYNCHDMLC not available in BEAMnrc gui

Fix a bug where the SYNCHDMLC module was not available when creating a
new accelerator in the BEAMnrc gui. This was due to a hard coded value
for the number of component modules in create_accel.tcl. Now the length
of the cm_names array is determined correctly.
marenaud/EGSnrc,marenaud/EGSnrc,crcrewso/EGSnrc,mchamberland/EGSnrc,ftessier/EGSnrc,MartinMartinov/EGSnrc,crcrewso/EGSnrc,nrc-cnrc/EGSnrc,nrc-cnrc/EGSnrc,ftessier/EGSnrc,nrc-cnrc/EGSnrc,marenaud/EGSnrc,ftessier/EGSnrc,crcrewso/EGSnrc,mchamberland/EGSnrc,nrc-cnrc/EGSnrc,mchamberland/EGSnrc,marenaud/EGSnrc,MartinMartinov/EGSnrc,mchamberland/EGSnrc,mchamberland/EGSnrc,MartinMartinov/EGSnrc,crcrewso/EGSnrc,nrc-cnrc/EGSnrc,MartinMartinov/EGSnrc,ftessier/EGSnrc,ftessier/EGSnrc,ftessier/EGSnrc,mchamberland/EGSnrc,marenaud/EGSnrc,crcrewso/EGSnrc,MartinMartinov/EGSnrc,marenaud/EGSnrc