add template function to shift decimal points

[mmolnar]

This function will be usefull when you need to convert miliseconds to seconds.

I am not a go programmer, so doing tests would be difficult for me.

[coveralls]

Coverage decreased (-0.4%) to 68.957% when pulling 3554b54 on mmolnar:master into ad4273d on fstab:master.

[fstab]

Looks good, thanks. Maybe it would be clearer to use multiply instead of shift. With {{shift .val 3}} there are some implicit assumptions (decimal shift (not binary), shift is to the right (not to the left), order of the parameters is important (right is the exponent)). If we instead implement {{multiply .val 1000}} I think it would be clearer what it does.

Could you change it and make it multiply instead of shift?

[mmolnar]

OK, I have modified the commit to do general multiplication.
As templates can use go float literals I can just use scientific notation to simply achieve what I was aiming for:
{{multiply .val 1.e-6}}

[fstab]

Thanks!

[fstab]

I added add, subtract, and divide. So we have all four arithmetic functions now.