Browse By input field placeholder and help text improvements

[devangm]

On Browse By listing pages, the browse-by box has misleading text in it, saying "Search the Repository". It should instead reflect that it's a browse and not a search per se. Change to read "Enter the first few letters."

The help text below the Browse By box should change to "Enter the first few letters to jump to a point in the index. To instead do a general search, click here." The "click here" should link to an empty search for the community/collection context.

[jcreel]

Placeholder text: "Enter the first few letters"
Help text below: "Jump to a point in the index by entering the first few letters. For a general search, click here"

[jcreel]

Have requested that the search link go to the container context - see DSpace#324