Cleaning up pester.psm1

Swapped tabs for spaces, and standardized indenting.  Removed a couple of % and ? aliases.

Brace style is still inconsistent, for now.
Formatting cleanup

Replaced all tab characters with 4 spaces, and removed all trailing whitespace from the end of lines.

Some files have been manually reviewed to clean up indenting after this mass tab cleanup, but not many yet.  More to come.
More formatting cleanup

Manually reviewed all files under the Functions directory for indentation cleanup.

Replaced a couple of instances of usages of the % and ? aliases with foreach and where.
Merge pull request #170 from dlwyatt/FormattingCleanup

Formatting cleanup