devel/libosmo*: simplify and misc fixes

[jbeich]

Summary

• Unbreak on DragonFly
• Unbreak on big-endian archs [1]
• Unbreak and rename DOCS option [2]
• CONFLICTS with multimedia/libmtp [3]
• Convert to USES=autoreconf
• Convert to USES=pathfix
• Convert to INSTALL_TARGET=install-strip
• Convert to PORTDOCS
• Fix whitespace
• Bump PORTREVISION for [1], [2], [3]

PR: 197948
Approved by: Nikola Kolev <[e-mail]> (maintainer, waiting...)

Everything started from bug 197707. @pi is to review at least doxygen stuff he added in rP364505.

Test Plan

poudriere bulk -t 10.1R i386 logs:
http://slexy.org/view/s21CtTPpbr libosmocore-0.8.0 DOXYGEN=on
http://slexy.org/view/s2nHU1fuN9 libosmo-abis-0.3.1
http://slexy.org/view/s2Hnfm2m5w libosmo-netif-0.0.4
http://slexy.org/view/s2bQQhqp8Z libosmo-sccp-0.0.6.3_1
http://slexy.org/view/s2CVGh9r0P libosmocore-0.8.0

Also green on 8.4R amd64, 9.3R i386, 10.0R amd64.

[pi]

looks fine, I have not build-tested it.

[jbeich]

Closed by commits: rP379763, rP379764 (authored by @jbeich).