Create Relationships - Usability Improvements

Rationale
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Usability issues in current form flow:
1. If user selects a specific contact from auto-complete search field, the are still required to click the search button AND to mark the single contact returned from search. This flow can be streamlined

2. Sites with large DB's can get "Too many matching results. Please narrow your search by entering a more complete target contact name." - even when entering fairly complete contact name like 'Adams'.

Implementation
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1. If user selects a specific contact id from the auto-complete drop-down list, and hits Enter key, submit the Search form and display the 'Mark Target Contact...' fieldset WITH that contact row's checkbox already checked (i.e. "contact_check[xx]").... along with the rest of the form elements (i.e. Start Date, End Date, etc.).

2. We need to support any number of search results on this form (rather than imposing the current limit and giving the error message). This means implementing a paging mechanism within the "Mark Target Contacts... " fieldset (i.e. search results).

Preferred approach is an embedded page-able ajax grid (same as or similar to the Case Activities grid in Manage Case page). This allows paging without reloading the HTML page.

If that approach isn't feasible in this context, then we can implement our standard pager (i.e. same as in Basic and Advanced search results).