Define status items in para.h.

Define status items in para.h.

The only reason the status item enum and string array are defined in
configure.ac is that upper case identifiers and lower case strings
are not easy to do in cpp as it lacks toupper().

However, configure.ac is not the right place for defining C language
constructs as the configure script should only check for installed
packages.

This commit moves the definition of the status item enum and array to
para.h and modifies all users to use lower case for the item names.
This was automated with a script which essentially did

	upper=${i^^}
	sed -i "s/\<SI_$upper/SI_$i/g" $files

for each status item $i. Care has been taken to leave the order of
the status items unchanged. This is important because the item numbers
must be considered part of the API between server and client.