upgrade 3rdparty packages

uutf: 0.9.2 -> 0.9.3
xmlm: 1.1.1 -> 1.2.0
tyxml: 2.2.0 -> 3.0.0, regenerate oasis
findlib: 1.3.3 -> 1.4.1
pcre-ocaml: 6.2.5 -> 7.0.4
ounit: 1.1.2 -> 2.0.0
ocsigenserver: 2.2.0 -> 2.3.0 + 100-continue patch, disable ocsipersist build
upgrade ocamlnet to use patches from SVN instead of local path
lwt: 2.4.3 -> 2.4.4
cryptokit: 1.6 -> 1.9, regenerate oasis
do not require ocamldoc always
drop patched https_client
update .gitignore
require ocamlnet > 3.7.3
Merge branch 'upgrade'
SXproxy -> LibreS3
fix pid path
update hostname when generating .s3cfg
require ocamlfind >= 1.2.8
update build instructions for 3rdparty/libs/pcre-ocaml

it uses oasis build system instead of custom make now, so use the generic rule