Merge branch 'feature-clang-compat'

Fix network module (#21)

* [network/http] fixes #19 : boost and std shared_pointer are no longer mixed
* [network/http] fixes #20 : server replies with correct keepalive heaver
* [network/http] implements http client
* [network/http] get rid of ugly filter and handler structures replaced by c++11 variadic template args
* [network] replace many boost call to c++11 std
* [core] log config loader parses log_level case insensitively
* [core] log syslogappender no longer require options config property
* [core] moved url decode function to core text::url
* [tests] enable debug syslog logs in main test application
* [tests] adds handy "exec" function to default test fixture class
* [network] replace ThreadManager singleton by core mixin
* [network] fix ThreadManager destruction race condition
* xtdmake : bump version
* adds -Werror gcc flag

debianize package (#17)

* debianize package
* make build compatible with both local and system xtdmake
* adds boost in build dependencies
* catch up xtdmake new release 1.0.3
* generate libxtd0 libxtd0-dbg and libxtd-dev packages