workaround for old gcc version issue

Check if "inline" aggregate initialization works for array
class members. Use double braces initialization as a workaround.

test: add support for matching memcheck logs

Provide support for matching memcheck and pmemcheck output files.
Match file should follow pattern:
<testname>_<testcase_nr>_<tracer>.err.match

obj: fix pmem::obj::v<> to match new changes

Required due to the pmemobj_volatile API change.

tests: match logs automatically on test finish

common: use coverage flag to group metrics

Introduce pmem::obj::array

Imported from https://github.com/llvm-mirror/libcxx/commit/88f5d7a38bf379d2772a7c0b064b680d6eaea4dc

common: fix doc update script

tests: skip pmemcheck tests if pmemcheck is not found

Using git commit -a only staged modified or deleted files but new files were ommited.

common: fix some warnings on windows

reported by MSVC.

Update clang format

Add aggregate initialization support

which fixes unused variable warning in release build.

Warnings cleanup

On windows Wall contains all possible warnings (most of which is either
generated by windows headers or too pedantic - e.g. padding added by compiler)

and remove comment regarding clang-format (only 3.8 and 3.9 is supported)

to avoid -Wformat-security

common: update docker images

common: set codecov threshold to 0.2