account for trailing exponent in test call_function's regexp
ensure __STDC_FORMAT_MACROS is always defined

C99 specifies that this macro must be defined if <inttypes.h> is to work
as expected in C++ environments.  Including <cinttypes> works around
this, but given that a number of places already include inttypes.h, we
might as well define the macro and be done.
fix some format directive mismatches
fix templated calls to std::max

With 64-bit ssize_t, the compiler complains about not being to match the
types of a bare `0' and an ssize_t.  Explicitly casting to ssize_t(0)
helps the compiler out.
handle missing SYS_socketcall in test/block.c
fix int-to-pointer cast with mismatched sizes
remove unnecessary static_assert in replay_syscall.cc

The static_assert claims that we need a specific function for writing a
uint32_t, but the templated Task::write_mem handles writing the uint32_t
just fine.
remove 32-bit assumptions around DBG_COMMAND_MAGIC_ADDRESS
Rename TraceOfstream::flush to TraceOfstream::close.

When we implement compression, it's annoying to implement flush-without-closing.
Add CompressedReader/Writer for multithreaded zlib compression of streams.
Use CompressedReader/CompressedWriter for trace I/O.

Resolves #700.
Add -s option to 'rr dump' to dump statistics --- currently, compression statistics.
Add -b option to 'rr dump' to dump syscallbuf records.
Better error checking.
Disable slack in advance_to.
Treat any unexpected exit as an unstable exit. This ensures SIGKILL triggers unstable exits.

Resolves #1285.
Make ptrace-using functions more resilient to ESRCH errors due to target process being killed.
Don't update trace events if there is a ptrace event pending.

There could be a pending PTRACE_EVENT_EXIT due to unexpected SIGKILL of the
tracee. In this case we just need to bail out and return to the point where
the ptrace event can be processed.
Simplify guards around ptrace_handle_event.
EXIT events don't need EXEC_INFO, and sometimes can't get it since we can't get registers from a zombie process.