4.0.0

• Added im2col function.
• Added sign function
• Added randperm with 3 outputs. Third output specifies number of permutations
• Added gallery function and corresponding predefined literals. This function also includes magic, hilb, invhilb, hadamard, pascal, spiral
• Renamed std function.
• Removed functions: cell (can be easily substituted), spiral (included in new gallery function)