Don't expand paragraph boundaries outside the current root

The surround paragraph found by traversing the start or end container may
be outside of an inline root. OdtUtils.getParagraphElements has logic that
prevents traversal out of the current root into a new root.

Fixes issue #300
Removed duplicate function OdfUtils.getImpactedParagraphs
Merge pull request #306 from peitschie/triple-click-fix

Don't expand paragraph boundaries outside the current root