Define OSMAJOR as the OS major version, and add it to CFLAGS when
compiling libpkg sources.

Add new function: bool pkg_compiled_for_same_os_major(void) -- detect
when pkg(8) is running on a different OS major version than what it
was compiled for (presumably as a consequence of system upgrade)

Add INDEXDIR and INDEXFILE config file values to parallel the usage in
${PORTSDIR}/Makefile etc.  These are respectively the directory to
search for the ports index in (if undefined, defaults to the value of
PORTSDIR) and the filename of the index -- default INDEX-N where N is
the OS major version.
Fix typo.
Add some helpful advice for people doing major version upgrades.
Merge branch 'master' into indexfile
Overwrite an existing value if it exists in the pid lock table
Update libucl to latest version
Rework libucl import
Fix locks upgrade.
Fix upgrades check logic.
Actually we use 1.3.0 for this version.
Ignore isolated variables in the solver.
Add pkg_version_change_between function.

This function is intended to compare changes between two packages
passed. Its return value is similar to pkg_version_change.

Converted utils.c in pkg to use new API.

Fixed style a bit while I'm here.
Fix pkg self upgrade.
Another upgrade fix.
Upgrade fetching fix.
Fix deletion in case of upgrade.
Re-solve upgrade conflicts.
Increase solved counter in the upgrade job.
Process conflicts in case of upgrade.

Reported by: az
Autotoolizing