[boost] [iostreams] Check zlib/bzip2 availability on configuration checks

Subject: [boost] [iostreams] Check zlib/bzip2 availability on configuration checks
From: Kohei Takahashi (flast_at_[hidden])
Date: 2013-02-13 03:29:37

Hi all,

I attached a patch for preventing build error with the environment which
provides no zlib and/or bzip2.

This patch detects zlib.h and bzlib.h availability on configuration
checks timing. It also should work with any environment variable (e.g.
ZLIB_SOURCE,BZIP2_SOURCE, ...).

Suggestions and comments welcome.

Thanks,
Kohei Takahashi