libssh2 1.8.0, 1.8.1-20181201(test)

[Heavenly Avenger <avenger@avenger.ws>]

Hello!

The libssh2 (www.libssh2.org) package is way out of date in cygwin repo 
and no test/unstable available. I was frustrated with this and went down 
the trouble to build it myself.

I can't commit to become a permanent package maintainer but I'm sharing 
with you the cygport and package files in case somebody wants to update 
the official cygwin repositories.

I have built two package sets: libssh2-1.8.0 (which includes the same 
1.7.0's _1 and -devel subsets) and also libssh2-1.8.1-20181201 off 
latest daily from libssh.org. I needed public key compatibility with 
modern OpenSSH implementations, which was also absent from the 1.8.0 
release.

The cygport files for both package sets is at: 
https://avenger.ws/cygwin/cygport.

I built the packages and, in an attempt to follow the packages 
contribution guide 
(https://cygwin.com/packaging-contributors-guide.html), also am 
providing them here:

https://avenger.ws/cygwin/x86_64/libssh2/

I have manually added "test:" lines to 1.8.1-20181201 with the following 
script, because I believe this is the only way to tag packages as 
test/unstable:

----

#!/bin/bash
echo -n "Appending 'test:' to hint files: "
for hintfile in $(find */dist -name '*.hint' -type f); do
  if [ -z "$(egrep "^test:" "${hintfile}")" ]; then
   echo -n "."
   echo "test:" >> "${hintfile}"
  else
   echo -n ","
  fi
done
echo " done."
----

I just run this right after assembling the unstable package. As for what 
I could find in the mailing list archives, this is a manual process, and 
as the thread I found about it was somewhat recent (2017), I believe 
this is still not something supported in the cygport files. The test 
version is built with libssh2's debugging trace() enabled.

Hope this is a welcome contribution for the cygwin community!

p.s.: maybe libssh2 still has a maintainer around, so just letting them 
know, I could build it without any patch, so it should be easy to update.