* Replicate poco into base/poco/
* De-register poco submodule
* Build poco from ClickHouse
* Exclude poco from stylecheck
* Exclude poco from whitespace check
* Exclude poco from typo check
* Remove x bit from sources/headers (the style check complained)
* Exclude poco from duplicate include check
* Fix fasttest
* Remove contrib/poco-cmake/*
* Simplify poco build descriptions
* Remove poco stuff not used by ClickHouse
* Glob poco sources
* Exclude poco from clang-tidy
clang-tidy now also checks code in header files. Because the analyzer
finds tons of issues, activate the check only for directory "base/" (see
file ".clang-tidy"). All other directories, in particular "src/" are
left to future work.
While many findings were fixed, some were not (and suppressed instead).
Reasons for this include: a) the file is 1:1 copypaste of a 3rd-party
lib (e.g. pcg_extras.h) and fixing stuff would make upgrades/fixes more
difficult b) a fix would have broken lots of using code
This commit adds a number of changes to platform-detection and
compile-time directives required to support building ClickHouse on
Solaris-derived systems, most notably illumos.
