Strip whitespace from cells (R parsing code).

Fixes #1132.
Only table innards are stripped

Matches more closely with what we're doing in QIIME parsing code.
-e is now used on #!/bin/bash
Merge pull request #1136 from wasade/issue1104

-e is now used on #!/bin/bash
Merge pull request #1134 from jrrideout/issue-1132

Strip leading/trailing whitespace from cells (R parsing code)