Replaces the static Duplicate() method.

To make things simpler, AllocatedString is now a non-template class.

Use uri_has_scheme to find out if the href in Webdav responses is absolute
to use the matching base path extraction.
Signed-off-by: Vincent Petry <PVince81@yahoo.fr>

Closes https://github.com/MusicPlayerDaemon/MPD/issues/910

The ones in std have overloads for const char/char.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Needed for std::wmemchr under libcxx
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Fixes regression from commit db93bb99 because
ParseMimeTypeParameters() assumed the items were null-terminated, but
after that commit, they were not anymore.

_GLIBCXX_USE_C99_MATH_TR1 is the correct one.

_GLIBCXX_USE_C99_MATH is always defined.

Prepare to fix cc72ceb3

The _GLIBCXX_USE_C99_MATH macro is defined in glibcxx by c++config.h, which
gets included by every header. Which means a header needs to be present.

(cherry picked from commit 79e9aff3)

Eliminates lots of overhead.