Fix AntPathMatcher rule for combining with extensions

Before this fix AntPathMatcher had a special rule for combining
patterns with wildcards and extensions as follows:

"/*.*"  + "/*.html" => "/*.html"

This change ensures this rule never applies if the first pattern
contains URI variables.

Issue: SPR-10062
Update @RequestParam javadoc

Issue: SPR-10180
Catch IAE when parsing content type

Issue: SPR-10308
Fix DefaultMockMvcBuilder fluent API generic type

Changed upper bound of generic parameter for DefaultMockMvcBuilder from
MockMvcBuilder to DefaultMockMvcBuilder to allow for ongoing method
chaining in the fluent API style.

Issue: SPR-10277
Fix FreeMarker form checbox macro generated names

In Spring 3.2 a fix was implemented for all Spring Freemarker form
macros so that generated form input fields have valid bracketless IDs.
In the fix a regression was introduced manifesting in formCheckbox
macro no longer generating appropriate names for checkbox and hidden
input field.

This change fixes mentioned regression issue.

Issue: SPR-8732