adjust GDB & Valgrind easyconfigs to be ready for upstream submission

Signed-off-by: Fotis Georgatos <fotis.georgatos@uni.lu>
adjust headers as per discussion in easyblocks#101

Signed-off-by: Fotis Georgatos <fotis.georgatos@uni.lu>
add ncurses in dependencies of GDB

Signed-off-by: Fotis Georgatos <fotis.georgatos@uni.lu>
Merge pull request #101 from fgeorgatos/84_contrib_GDB_and_Valgrind

84 contrib gdb and valgrind