Release 2.49

Update latest tag to v2.48

Merge pull request srvrco#796 from srvrco/release_2_48

Release v2.48

Release 2.48

Release v2.47

Merge pull request srvrco#741 from srvrco/release2.46

Release 2.46

Merge pull request srvrco#719 from srvrco/timkimber/issue717

Fix upgrade url issue

Merge pull request srvrco#715 from srvrco/fix-preferred-chain-arg

Fix -preferred-chain argument (srvrco#712)
Show help if no domain specified (srvrco#705)

Compare version numbers properly

getssl uses cURL's version to determine what command
options are valid.

The previous shortcuts will fail when curl V8.10 is
released.  (8.9 is greater than 8.10).  V8 is planned
for release, in part to avoid a minor version of 100,
which also would fail.

check_version() will compare full or partial version
strings by component, and is true if $1 is at least $2.

Suppress test failure when release description contains "error"

Upgrade test checks for "error" in output.

But release descriptions can have "fix error in ..."

Don't run this check.  Checking that a new version is detected suffices.