Fix missing signs for triangular BLAS2 functions

The PENCIL wrappers for triangular BLAS2 functions with reverse vector
access lacked a minus sign.  This was because 'arrayCases' contains
the cases for both the matrix and the vector.  Unfortunately, the case
'n' was used for both the matrix and the vector, with different
meanings.  We change the 'n' case (non-unit-triangular) for matrices
to 'e', such that each different case now uses a different letter.

Change-Id: I010a2c8dce4afe9de7c1597fc963bd0c9fe5e746
wrapper.py: avoid overwriting name variable

The variable 'name' holds the BLAS function name in genWrapper.  We do
not want to have this overwritten by something else, because we need it
later on.

Change-Id: I1d1e5d28cae23852f6e2f3d26ef62288e95959fd
Emit warning for invalid wrapper case

Change-Id: I74436c60f9cf1ee5af51c0ca4e673f69ecbbdbc3
wrapper.py: fix pwrapper array sizes

Change-Id: I9a5200ced3d45294942f53ab7b50f120b092e634
Reviewed-by: alekra01
wrapper.py: add quick return for m

Change-Id: Iddb6318fd97281e838094a4094c7f948e1c235be
Reviewed-by: alekra01
wrapper.py: add assume statements to pwrapper

These are BLAS-specific assume statements that we cannot reasonably
expect the VOBLA compiler to generate.

Change-Id: Ib6d77b20d71ee0ed241ff8017de0c86f7e6bb323
Reviewed-by: alekra01