1.1.11 update:
	Add "workdir" and "keep" option for sfold, which allow users to decide.
	Replace fc.constraints.find('|') to '|' in fc.constraints.

1.1.12 update:
	Genes with duplicate names are ignored to avoid ambiguity.
	Instead of using tempfile names, here we use sequence names.
	Replace s.find('(') with '(' in s statement.

1.1.13 update:
	fix bugs in FastD.toFastC('exclusive') method. New method was used to speed the fisher exact test.

1.1.14 update:
	add depth function for FastD class
	add bpReader function to read sfold folded structrues and centroids

1.2.0 update:
	Add examples folder for demo examples.
	Fix bugs in Fasta.rc(), which doesn't reverse the sequence.

1.2.1 update:
	Remove python 2.6 support.
	updated the requirements list.
		Removed scipy. Added fisher instead.
		Removed scikit.

1.2.2 update:
	Fix sfoldext bugs. Display the warning information of sfold.

