clarify license for generated headers

Invocation and syscall headers are generated and provided under
BSD-2-Clause for user code and GPL-2.0-only for kernel code. To
facilitate people other than the copyright holder performing this
operation, the master files are provided under both (BSD or GPL, free
to choose).

Convert license tags to SPDX identifiers

This commit also converts our own copyright headers to directly use
SPDX, but leaves all other copyright header intact, only adding the
SPDX ident. As far as possible this commit also merges multiple
Data61 copyright statements/headers into one for consistency.

mcs: scheduling context donation over ipc

After this commit, threads blocked on an endpoint can recieve a
scheduling context from the thread that wakes the blocked thread.

python2 --> python3

Update all scripts and build system to call python3, given python2's
upcoming doom. Use sys.maxsize instead of sys.maxint in one script
(maxint does not exist in python3).

style: run autopep8 on python files

tools: State jinja2 version

Provides a graceful error when jinja2 is the wrong version

tools: Correct syscall numbers

tools: Fix whitespace differences in header gen

libsel4: change tempita to jinja2

libsel4: follow style conventions in python scripts

This commit makes some constant variables upper case to follow the style guide.

tools: fix licenses

libsel4: fix licenses

- some were incorrectly marked GPL (libsel4 is BSD)
- update NICTA --> DATA61 etc
- fix tags D61 --> DATA61
- update year to 2017

Debug: avoid syscall_names unsued Werror when debug mode is enabled

debug: generate list of syscall names

tools: syscall_header_gen: print an error to stderr that wasn't

tools: syscall_header_gen: python3 compat

tools: syscall_header_gen: remove trailing whitespace

Change types from uint32_t->word_t to be 32/64bit agnostic

Config sections in syscall.xml files take a condition which is passed to #if.

ia32: Move as much of the interrupt and syscall traps into C as possible

Use usr/bin/env for all python bangpaths to enable virtualenv use.

Very useful with python3 as the default platform.

Release snapshot