Export inline accessors for memLow/memHigh

This patch adds sasindexnode.h to libsphdeinclude_HEADERS in src/Makefile.am
so that that include file will be exported by make install.And some minor
performance fixes. Changes some automatic variables from short to long which
avoids extend sign ops. Adds sasallocpriv.h to export inline accessors for
memLow/memHigh which are visibility hidden.

	* ./src/sasallocpriv.h: New file.
	* ./src/sasalloc.cpp: Include sasallocpriv.h.
	(setSASFinder): Use getfastMemLow().
	(getSASFinder): Use getfastMemLow().
	(SASFindHeader): Use getfastMemLow() and getfastMemHigh().
	* ./src/sasindexnode.cpp: Include sasallocpriv.h.
	(SASIndexNodeKeyMove): Use getfastMemLow() and getfastMemHigh().
	* ./src/sasstringbtreenode.cpp: Include sasallocpriv.h.
	(SASStringBTreeNodeKeyMove): Use getfastMemLow() and
	getfastMemHigh().
	* ./src/sphcontext.cpp: Include sasallocpriv.h.
	(SPHSetupProjectContext): Use getfastMemLow().
	(SPHSetupAltProjectContext): Use getfastMemLow().
	(SPHRemoveProjectContext): Use getfastMemLow().
	(SPHDestroyProjectContext): Use getfastMemLow().
	* ./src/sasindexnode.cpp (SASIndexNodeSplit): Change short int
	to long int for performance.
	* ./src/Makefile.am (libsphdeinclude_HEADERS): Export
	sasindexnode.h for make install.
	* ./src/Makefile.in: Regenerate.