MFH: r407158 devel/py-trollius: Fix Python 3.x build, Modernize

• Correct LICENSE (MIT to APACHE20)
• Add LICENSE_FILE
• Remove BUILD_DEPENDS, futures (and most python packages) are RUN_DEPENDS
• Conditionalise futures RUN_DEPENDS. Only required on Python < 3
• Sort USE_PYTHON
• Add NO_ARCH
• Add test target and TEST_DEPENDS

QA:

• portlint: OK (WARN: Makefile: "RUN_DEPENDS" has to appear earlier. - False Positive)
• testport: OK (poudriere: 11amd64, Python 2.7 / 3.4)
• unittest: OK (Ran 845 tests in 23.226s - FAILED (failures=3, skipped=1) False Positives, fixed in version 2.0

PR: 205078
Approved by: portmgr (blanket, ports compliance)

Approved by: ports-secteam (feld)