changelog
	version 2.8.1
		- substructure viewing support
	
	version 2.7.2
		- updated 'atomsubset' function
	
        version 2.7.1
		- SDFset() constructor
        
	version 2.5.8
		- corrected sim.R file 
        
	version 2.5.7
		- updated 'atomsubset' function
	
	version 2.5.6
		- added 'atomsubset' function for returning substructure from SDF/SDFset

	version 2.5.5
		- Documentation updates

	version 2.5.4
		- added 'rings' function for ring perception and aromaticity assignment  
                - added 'groups' function for counting functional groups

	version 2.5.3
		- fixes for plotStruc/plot to show charges, disconnected
                  atoms and missing hydrogens of non-C atoms

	version 2.5.1 - 2.5.2
		- Utilities for adding missing hydrogens: includes new 'bonds' function
                  that is used by functions 'atomcount', 'MW', 'MF', 'atomcountMA'
		
        version 2.2.16 - 2.2.18
                - Added conMA function to create connection matrices
                - Documentation updates

        version 2.2.15
                - documentation updates
		- renamed searchSub() to searchSim()
		- wrapped web service code in man files with \dontrun{} 

	version 2.2.14
		- introduced support for ChemMine Web Tools including PubChem searches

        version 2.2.12 - 2.2.13
                - help file updates
                - fix for SDF import to support Drug Bank data
	
        version 2.2.0 - 2.2.11
		- added support for PubChem fingerprints
	
        version 2.1.5
		- added validSDF function

	version 2.1.4
		- minor bug fixes
	
        version 2.1.3
		- minor bug fixes
        
        version 2.1.2
		- minor bug fixes

	version 2.1.1
		- introduced S4 classes for all object types
		- added full support for processing SD files
		- added compound depictions with R's graphics device
	
	version 1.2.4
		- bug fix for 1.2.3

	version 1.2.3
		- enhance cluster visualization 

	version 1.2.2
		- minor bugfixes

	version 1.2.1
		- use ChemmineR Performance Pack (ChemmineRpp) when available

	version 1.1.1
		- updated Vignette
		- sdf.visualize now accepts dataframe for argument 'extra'
		- sdf.visualize now accepts names for reference.note
		- cluster.sizestat now handles clustering result with multiple cutoffs

	version 1.1.0
		- enhanced cluster.visualize
		- add db.subset

	version 1.0.9
		- check cmp.similarity arguments
		- improved compound visualization: now allow a reference compound
		- now search has built-in visualization

	version 1.0.8
		- sdf.visualize reads CIDs and allows extra description on
		  compounds
		- in cmp.cluster, is.similarity is now the default
		- db.explain now returns value rather than printing it
		- cluster.visualize now outputs to EPS and PDF

	version 1.0.7
		- document changes
		- add `quite' options to many functions
		- more robust parsing
		- better handling of progress messages

	version 1.0.6
		- add sdf.visualize

	version 1.0.5
		- use readLines instead of scan in parsing MOL table

	version 1.0.4
		- fix unclosed I/O connections

	version 1.0.3
		- add cmp.duplicated
		- rename 'cluster' to 'cmp.cluster'
		- column names of clustering result now contain no space
	
	version 1.0.2
		- cluster now accepts ... arguments for cmp.similarity

	version 1.0.1
		- add sdf.subset
		- add db.explain
		- add cluster.sizestat
		- add cluster.visualize