userspace/libsinsp/filter: make next_operand return vector<char>

Modify sinsp_filter::next_operand to handle operand which contains
the NUL terminator.
userspace/libsinsp/filter*: modify parse_filter_value to accept len

When the filter value is binary, we need to pass the length of the
value.
userspace/libsinsp/filter*: extend rawval_to_string to accept PT_BYTEBUF
userspace/libsinsp/filter*: evt.buffer return raw_value when m_is_compare
userspace/libsinsp/filterchecks: some refactoring
userspace/libsinsp/filter*: transform evt.buffer in PT_BYTEBUF
userspace/libsinsp: remove old code
userspace: remove some trailing whitespace
userspace/libsinsp/parsers.cpp: filter out events about sysdig digs sysdig
userspace: add option to enable sysdig to capture events about itself
userspace/libsinsp/parsers: fix compile error on windows
[53] Build for Solaris

Adds the necessary code splits for GNU make and SunOS -l flags into
the CMakeLists.

Changes the pragma rules for SunOS g++ (which do not support pop)

Also adds some minor include file preprocessor branches with __sun
tests.
Make access_ok work even when grsecurity is enabled. #76
[28] Complete quoting for parameters of some CMake commands

Adds quotes where applicable for variables inside of the CmakeLists
files
fix error message so that it is reachable and matches other checks in kernel driver
No longer including unistd_32.h or unistd_64.h. The kernel knows what to do

The kernel knows its configuration, and will pick the correct unistd.h
No longer assuming that syscall IDs start at 0

This is a valid assumption for x86, but not for many other arches (per-EABI ARM,
MIPS, etc).
presense of __NR_socketcall is now checked more directly

Previously we were looking at __x86_64__ to see if we had that system call. Now
I directly look at __NR_socketcall, which is more portable
generic __x86_64__ -> CONFIG_X86_64
Checks for split 64-bit syscall arguments are more portable

This is described in syscall(2). Some syscalls take 64-bit arguments. On
arches that have 64-bit registers, these arguments are shipped in a register.
On 32-bit arches, however, these are split between two consecutive registers,
with some alignment requirements. Some require an odd/even pair while some
others require even/odd. For now I assume they all do what x86_32 does, and
we can handle the rest when we port those.