Allow ALTER TABLE ADD ( column ) syntax.

        * (src/backend/Makefile): Use `ln', not `cd;ln' so that installers
        can wrap ln.

Add appropriate HAVE_{RANDOM,SRANDOM} values to config.h
Add approrpiate #ifdef's to sparc_solaris port files for Solaris v2.6

              ^^^^^^ - new order of tuples (due to psort changes)

Use qsort to sort array of tuples for nextrun when current
run is done and put into leftist tree from sorted array!
It's much faster and creates non-bushy tree - this is ve-e-ery good
for perfomance!

	lt_tupcount - number of tuples in struct leftist *Tuples
	lasttuple   - last tuple put to disk by createfirstrun()

2. Limit number of tuples in leftist trees:
	- put one tuple from current tree to disk if limit reached;
	- end run creation if limit reached by nextrun.
3. Avoid mergeruns() if first run is single one!

	(default value for max number of tuples in leftist tree)

(-S memory,tuples)

 including DROP COLUMN, SET CONSTRAINT, etc.

 after adding separate sections for DEFAULT and CHECK.