also put INSERT_PRODUCTS_PATH in erp5testrunner's sys.path

Tests directory of inserted paths also needs to be in sys.path so that tests
can import other tests.
Update eggs version
Fix CHANGES rst syntax.
version up : ghostscript 9.07.

* enable thread safe
* build without libidn
version up : poppler 0.22.2.
version up : libcroco 0.6.8, librsvg 2.36.4.

(librsvg 2.37 requires newer pango.)
Sanitize input.

TODO: Would be better to sanitize every parameter at beginning.
Sanitize inputs in apache recipe.

Avoid Nonetype-related errors.
Temporary forbid activation of cache until it is properly tested.
Don't touch to custom conf file if already present
Update frontend documentation.

Explain custom configuration files.
version up : erp5.util = 0.4.33 and add zodbanalyze.
disable thread safe in ghostscript-9.07

because the output seems broken with enabling thread safe.
Merge branch 'erp5-component' into erp5
Merge branch 'erp5'