MSA highlighting that is based on conservation level

Conservation level of symbols in a multiple alignment is an important aspect during variation analysis.
Variations may be highlighted by their conservation level. To not to do distract attention of users with unimportant variations or, on the other hand, stress important ones.
A threshold of conservation % has to be introduced to control the highlighting level.
The feature is inspired by: http://www.bioinformatics.org/strap/toHTML/