Fixed escaping path names in the webapp

Path names and links needed to be properly escaped
Make parseMemorySize handle PB size

We need to use java BigDecimal to multiply the parsed size with the
petabyte size, since doubles loose precision at that magnitude.
Merge pull request #163 from manugoyal/html-escape-fix

Fixed escaping path names in the webapp
Moved PBDecimal definition to CommonUtils

Since it's only used there.
Cleanups
Merge pull request #164 from manugoyal/handle_pb

Make parseMemorySize handle PB size