server: don't raise error anymore if themes_dir is invalid or legacy blog can't be created: legacy blog will be entirely removed with 0.8 release, and themes_dir is only used by it. This patch limit troubles with this old code by not raising an error anymore if option is wrong or if the legacy blog can't be created. fix 317

import os.path

version_file = os.path.join(os.path.dirname(__file__), "VERSION")
try:
    with open(version_file) as f:
        __version__ = f.read().strip()
except NotImplementedError:
    # pyjamas workaround
    __version__ = "0.7.0D"