Enhancements to getting and validating element counts

[aaltat]

• Deprecate Locator Should Match X Times, Xpath Should Match X Times and Get Matching Xpath Count.
• Instead Locator Should Match X Times and Xpath Should Match X Times users should use: Page Should Contain Element keyword with limit argument.
• Instead of Get Matching Xpath Count create Get Matching Locator Count.

[pekkaklarck]

As discussed in comments of PR #950, the plan is that Get Matching Locator Count returns an integer, not string. This is different to Get Matching Xpath Count.

[aaltat]

Discussed with Pekka and we did decide the following:

• Rename Get Matching Locator Count to Get Element Count
• Deprecate silently also Locator Should Match X Times and enhance Page Should Contain Element to take in optional count argument
• When Page Should Contain Element keyword count is None it should match to one or more elements. Just like the current keyword works
• When count is number it should fail if number elements does not match.
• Optional, count could be also a range, defined like x..y. Where x < y. Keyword should pass if x <= element count <= y

[aaltat]

Decided not to do x..y support in this issue. It is useful feature but, it is more important to get 3.0 rc1 out.