completed work on variable tags removal

all tests are passing but this code isn't tested in practice
removed redundant result removal code
added eval with octave , fixed yank for :Crunch

still need to add control over using octave maybe an -o command or just
an option
Small improvements & fit on 80 columns - Crunch
Small improvements & fit on 80 columns - CrunchLine
added octave interface command
merged new changes

added
octave evaluation
improved yank into default register
small fixes, remove trailing zeros in ".10"
if using other eval method don't convert to float
small changes, improve octave integration

also added exception for floats that were too long
changed tag references to variable references
fixed variablevalue error
Merge pull request #17 from arecarn/mMontu-Dev_tags

M montu dev tags
make lines  <= to 78 characters in help
removed 'var' from variable definitions
Added implied multiplication to tags

allow an expression like x5 to evaluate to x*5