C header file now used as opencmiss/iron.h
Add Python script for updating Fortran code to new prefix

Also updates the problem and equations specification to be set
with an array.
Convert problem specification to an array

Rather than having separate class, type and subtype attributes, the
problem type now has a specification array that is allocatable so can be
an arbitrary length to provide more flexibility when specifying
problems.
Change equations set specification to an array

Rather than having separate class, type and subtype attributes, the
equations set type now has a specification array that is allocatable so can be
an arbitrary length to provide more flexibility when specifying problems.
Fix some "setup subtype" mess
Fix some cases where problem and equations set subtype were mixed up