common v1.0.1

• Initial version with following functions:

• labels.data.frame(): Adds, views and removes labels on a data frame.
• sort.data.frame(): Sorts a data frame.
• %p%: An infix operator for the paste0() function.
• %eq%: An infix operator to determine equality between two objects.
• roundup(): A function that rounds 5 away from zero.
• Sys.path(): A function to get the path of the currently executing program.
• v(): A quoting function for non-standard evaluation.