v0.7.0

This release includes some significant changes that unfortunately are not backwards compatible, mentioned below:

• Support for specifying open file handle limit (see #56).
• Experimental support for systemd, with some specific changes for Debian (see #13, #59 and #68).
• Support for creating custom coordination logic when restarting Kafka (see #58).
• host.name attribute is not set by default (see #62).
• Certain path attributes are now lazily initialized (see #61 and #64).
• Support for installing Kafka from source has been removed (see #66).
• Each version of Kafka is now installed into a version specific directory and then symlinked to the install_dir location. Backwards incompatible. (see #16 and #70).
• Other various small fixes.

Thanks to all contributors for tracking down bugs and making fixes. Sorry about the backwards incompatible changes. Unless something else comes up, the next release will most likely be v1.0.0 and from then on there won't be any backwards incompatible changes without a major version bump.