Testing modification of missingno to take threshold of missing data.
added percent_missing to internal.r
default bruvo.boot changed to upgma
missingno manual updated
missingno updated
Sandbox returned to its original state
updated vignette
edited percent_missing and .file.type

The percent missing for genotypes will be counted based on the number
of missing loci as opposed to missing potential alleles.
poppr function updated

added cutoff value to poppr function to pass on to .file.type
added cutoff value to man page
vignette update
added cutoff argument to poppr manual
Added clarity to .file.type
removed grey backgrounds in plots
changed spelling
added cutoff value to poppr
Added documentation to internal functions
updated documentation for internal sampling
removed sapply statements from mlg.vector + doc
replaced apply functions in mlg.crosspop