Squash working commits to avoid having the reverts in history, remove unnecessary test

Squashed commit of the following:

commit ff71ace85149e9a27846525732720deefbf4da79
Author: David.Um <david.um@lge.com>
Date:   Fri Sep 5 13:36:18 2014 +0900

    BHV-11591 The first index is a lowest index when user empties collection

    Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com

commit cc6306a3c9aed1a38d1ea83fc56265ae4467d9f9
Author: David.Um <david.um@lge.com>
Date:   Fri Sep 5 10:42:26 2014 +0900

    Revert "BHV-11591 Just for empty collection, make the first index as a low"

    This reverts commit 44dd195c64dfcc1afb30bc7cd65cce0b80f45daa.

commit 44dd195c64dfcc1afb30bc7cd65cce0b80f45daa
Author: David.Um <david.um@lge.com>
Date:   Fri Sep 5 10:38:34 2014 +0900

    BHV-11591 Just for empty collection, make the first index as a low

    Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com

commit 949e4ce9010b7c224597c99bd35b5807183f2d6f
Author: Cole Davis <cole.davis@lge.com>
Date:   Thu Sep 4 09:57:58 2014 -0700

    don't unnecessarily call indexOf on unordered array

    Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)

commit 22297e864c5d441e4634a0f9479d44634750974e
Author: DavidUm <david.um@lge.com>
Date:   Thu Sep 4 14:55:26 2014 +0900

    BHV-11591 Make consistency with medelsRemove()

    Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com

commit ed0d32cdc2b4567d56b8734c12e148fb5d253de3
Author: DavidUm <david.um@lge.com>
Date:   Thu Sep 4 13:40:14 2014 +0900

    BHV-11591 Reduce calculation and fix logic fault.
    Some cases, low could not be '0'

    Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com

commit 882ad24ec6fe76fe0b82259a88e03f1eca5c8356
Author: Cole Davis <cole.davis@lge.com>
Date:   Wed Sep 3 14:16:04 2014 -0700

    fix bad context

    Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)

commit 08709153308dbc28b0ef955408297f14feef7483
Author: Cole Davis <cole.davis@lge.com>
Date:   Wed Sep 3 13:48:37 2014 -0700

    only refresh pages when it is necessary

    Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)
Merge pull request #848 from enyojs/BHV-11591-final

Fix for: BHV-11591

Finally...

Reviewed-By: Cole Davis (cole.davis@lge.com)
Update version string to 2.5.1-pre.7