Add fortran support

[feodorp]

Adds Fortran endwise pairings:

• program name / end program name
• module name / end module name
• submodule (modname1:modname2:...) name / end submodule name
• [prefix [type]]functionname() / end function name
• [prefix]subroutinename() / end subroutine name
• type, [[attr...]::] name / end type name
• [label:]do / end do
• [label:]if / end if
• [label:]associate / end associate
• [label:]select case/type/rank / end select
• [label:]block / end block
• [label:]forall / end forall
• [label:]critical / end critical
• [label:]where / end where
• [abstract] interface / end interface
• enum. bind(c) / end enum