Cart page cleanup and general css improvements.

CSS cleanup and improvements on Cart page.
Minor css adjustments in page/form.less.
Cleaned/moved lot of css from page/page.less.
Created catalog/general.less to handle common catalog styles.
Created checkout/general.less to handle common checkout styles.

Local.xml
- Added css/catalog/general.less in following handlers:
--- <catalog_product_view>
--- <review_product_list>
--- <review_product_view>
--- <catalog_product_compare_index>
--- <catalog_category_default>
--- <catalog_category_layered>
--- <catalogsearch_result_index>
--- <catalogsearch_advanced_result>
--- <tag_product_list>
--- <checkout_cart_index>
--- <checkout_onepage_index>
--- <customer_account>

Added css/checkout/general.less in following handlers:
--- <checkout_cart_index>
--- <checkout_onepage_index>
ChangeLog.