EPICS @ RTEMS builds: separate BASE and TOOLS locations

[Ralph Lange <Ralph.Lange@helmholtz-berlin.de>]

Hi,

we decided that we want to keep the RTEMS core and the RTEMS toolchain 
at separate locations.
To allow that I'm about to commit the following change to 3.14 and the 
trunk:
1. Add a definition of RTEMS_TOOLS to 
configure/os/CONFIG_SITE.Common.RTEMS, and set it to $(RTEMS_BASE) for 
full compatibility.
2. Change all the paths to toolchain apps in 
configure/os/CONFIG.Common.RTEMS* to use RTEMS_TOOLS.
(3. Leave RTEMS_BASE unchanged when searching Makefile includes and 
adding to LD_LIBRARY_PATH.)
Objections?

Cheers,
Ralph