hol_light: fix wrong paths in hol.sh, copy src to lib
This patch fixes hidden bugs in hol_light's opam which did not reveal when installing hol_light locally,
but appear when installed from remote git.
Also, this patch copies the source files in the build directory to hol_light:lib because all .ml files
can actually matter when hol.sh is used in HOL Light.
My previous patch was my first contribution to OPAM, so these points were missed. :/
Since I didn't publicly announce the new HOL Light package, and this is a bug fix in its OPAM configuration,
I believe (hope) incrementing its version to 3.0.1 is not necessary.