Early buffer implementation for the Java codegen
modify RTS so that it can be built single-threaded if pthreads are not available.
fixups for HAS_PTHREAD changes
hack in idris_gc to force 16-bit/2-byte alignment for
allocations. Some embedded platforms, like the arduino/avr, support
byte-aligned pointers. However, that makes implementing tagged
pointers very tricky. So, instead we just force 16-bit alignment.
remove #include <unistd.h>. Not all platforms provide that header, and it does not seem to be required anyway.
force tag_arity and ty to be uint32_t instead of system dependent int sizes.
Changed some ints to size_t. Seems valid -- not certain.
should have been in the last commit.
Change + to | because | better reflects our intentions.
alloc_heap also requires the pointer alignment hack.
Minor fixes for the Java backend
Merge branch 'master' into JavaBackendFixes
* Make regression test029 work by adding a wrapper loading environment variables to properties
* Include sugar004
added "prim__registerPtr" noop for Java
Merge branch 'JavaBuffers' into JavaBackendFixes

Conflicts:
	src/IRTS/CodegenJava.hs
Add an optional depth to 'search' tactic

Also add it to Language.Reflection.  It's now good enough to work with
the proof obligations in Effects, so replace the old proof search (it's
also noticeably faster in larger programs).

Requires ibcs to be rebuilt.
Add :loadto command

Loads an input file up to the declaration beginning at the given line,
discarding any declaration after that.

This only really makes sense when developing interactively: it means you
can work on something at the top of a file without worrying about how it
affects what happens later (this also potentially makes it a lot
quicker!)

Latest idris-vim uses this.
IDESlave support for setting the depth of interactive proof search
Check that proof steps introduce no new problems

In interactive mode only (it is important that proofs can fail
temporarily during elaboration since futher information may help refine
the goal).

Fixes #1243
Merge pull request #1251 from david-christiansen/ideslave-proof-depth

IDESlave support for setting the depth of interactive proof search