adding HyperMesh and Patran BDF file support in pyMeshloader

[timryanb]

These fixes should help users who are trying to run pytacs with bdf files generated by HyperMesh:

• Changing default component naming from "untitled" to "Property group {pID}", where pID is the property Id number
  • This allows user to still have unique component labels when exporting to tecplot
• Adding check in meshloader to remove any empty property groups after reading in the bdf file
  • Empty property groups (groups with no elements associated with them) apparently cause f5totec to exit w/ an unsupported element types for f5totec error
• Adding HyperMesh and Patran component name parser to meshloader