Boost packages should include b2_options

[chrahunt]

Description of Problem, Request, or Question

I needed to debug my usage of boost_log/1.66.0@bincrafters/stable. By default the library is not built with debugging symbols. I was able to get a debug build by changing the conanfile.py in conan-boost_log to include

class BoostLogConan(ConanFile):
    options = {"shared": [True, False], "b2_options": "ANY"}
    default_options = "shared=False", "b2_options="

    def b2_options(self, lib_name):
        return str(self.options.b2_options)

After this, setting boost_log:b2_options=variant=debug in my Conanfile gave me the result I was looking for.

Can we add a check for conanfile.options.b2_options in boost_package_tools? This could make all of the modular Boost packages flexible for the end-user without needing to encode every b2 feature in each individual Conanfile. Individual Boost packages could be updated with the new option as-needed or proactively.

Package Details (Include if Applicable)

• Package Name/Version: boost_*/*