Update ui.jqgrid.css
Fix font size

jQuery UI (see [here](https://github.com/jquery/jquery-ui/blob/1.10.3/themes/base/jquery.ui.theme.css#L24-L30)) defines already rules with two selectors (`.ui-widget input`). The suggested rule force usage of the correct font inside of grid view.
Fix text-overflow:ellipsis for Mozilla
removing usage of global cancelPrm variable
Update grid.inlinedit.js

Initial value `{}` of `cancelPrm` or `tmpParams` will be always overwritten. Usage `o.editParams` during initializing reduces the code a little.
fixing usage of `if(undefined>=0)`

The condition `if(fr >= 0) {` can be used with `fr=undefined`. In general `undefined>=0` is false, but initializing of `fr` to `-1` seems me more reasonable.
fix the name of jQuery UI CSS class ui-corner-bottom
fix usage of $elem.val(undefined)
fix calling of custom_value with "set" and undefined value
replace 0px to 0
replace 0px to 0
replace testing for undefined to the testing for null or undefined to prevent warning of usage cm.searchtype below
replace 0px to 0
fixing possible usage of null.toString() or undefined.toString()
prevent exception in case of usage footerData(null, ...)
Merge pull request #534 from OlegKi/master

small fixes found with respect of JetBrains ReSharper 8.0.2