Fixed bug due to Zikula was not installable.
Slightly improved installer design.
Merge pull request #1575 from cmfcmf/installer-fixes

This PR was merged into zikula:1.3 branch.

Discussion
----------

Installer fixes

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | ---
| Fixed tickets | ---
| Refs tickets  | ---
| License       | MIT
| Doc PR        | ---


Commits
-------

b6547a309f8825a02e00df053bd781274309db6a Fixed bug due to Zikula was not installable. cmfcmf
a732d98c798fb783571ebb4f1f553da841753aa9 Slightly improved installer design. cmfcmf