do not fail if there is no ipv6
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
avoid assertion when opening non existent /proc/net/(tcp|udp|raw)6 files
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
honour already set C(XX)?_FLAGS

that way we can pass additional flags from the build-environment
Change permissions
rename install-sysdig to install-sysdig.in so it's more obvious that people should not run this
Merge pull request #75 from lazy404/ipv6Fix

sysdig fails to start if ipv6 is disabled
Merge pull request #80 from evgeni/honour-cflags

honour already set C(XX)?_FLAGS
userspace/libsinsp/parsers: fix compile error on windows
Skip a line from /proc/net/unix if the name contains bogus binary data. fixes #77
fix potential memory leak when invalid line is skipped