[postgis-devel] scripts version

[strk at refractions.net]

The missing distance_sphere() has been added to the lwpostgis.sql file.
This requires another scripts version upgrade.
The scripts version has 3 numbers, what I've been in mind
has always been giving them a meaning associated with the
ability to upgrade.
Unfortunately there's currently a single way to easily upgrade, which
is a dump-restore, but for these kind of upgrades it would suffice
to add the missing-function definition.
If we split the lwpostgis.sql file in two parts:
	- safely replaceble functions (no deps)
	- not safely replacable function (deps)
We might allow for a simple upgrade on functions addition or procedural
functions changes (w/out return or args type changes).

We could then use a MICRO version increment to specify sourcing the
lwpostgis_funx.sql file would suffice to get in sync with release.

The build scripts would nonetheless generate the full lwpostgis.sql file
concatenating the lwpostgis_funx.sql and the lwpostgis_code.sql files.

As for MINOR and MAJOR version meanings I wouldn't define a meaning now
but would wait until we have a need for them.

What do you think ?

--strk;