https://github.com/lxml/lxml/pull/10

Currently static builds look in 'libs' for downloads. This patch makes that directory configurable using the DOWNLOAD_DIR environment variable or the --download-dir= command line option.

When using zc.buildout eggs, are built in a temporary directory, making it impossible to supply lxml with the appropriate tarballs. I would rather use the inbuilt static build support rather than resort to z3c.recipe.staticlxml. After downloading the tarballs to the appropriate location, with this change I can now specify:

``` [lxml] recipe = zc.recipe.egg:custom egg = lxml environment = lxml-env

[lxml-env] STATIC_DEPS = true DOWNLOAD_DIR = ${buildout:directory}/lxmldownloads LIBXML2_VERSION = 2.7.8 LIBXSLT_VERSION = 1.1.26 LIBICONV_VERSION = 1.14 ```

Laurence