Fix color filtering bug

When we tried to filter products collection using the filters control
elements in the right panel, we got the error `You cannot define a
correlation name 'color_idx'`. The cause was in `catalog/layer_view`
block, which was added in the core magento `catalog.xml` by default and
also was duplicated in the custom `local.xml` layout file.
To fix it we need to remove one of the block instances.
Well, it's not so easy to do it as expected. The simpliest way was to
get a refernce on `left` container block and use `unsetChild` method
with `catalog.leftnav` as parameter. But it had no effect.
So, the solution is to remove `left` block totally using
`<remove name="left" />` in the `default` section of the `local.xml`
file.
Remove `comare products` blocks and links
Modify complex product items layout
Display some custom attributes
Add custom options to the product page layout
Remove stupid code which generated custom attrs