improve examples
remove useless @author comment strings
use more descriptive name than X for a class
rearrange readme: put most important material at the beginning
consolidate examples in subdirectory
docs: consolidate and extend context-sensitive rules in README; fix capitalization of NMR-STAR
document additional context-sensitive constraint
fix incorrect paths in test and example
refactoring: merge ast and buildast into single new module -- starast; no changes to functionality otherwise
extend range of context-sensitive checks with new NMRSTAR AST; extend parser and tests correspondingly
refactoring: rename modules
docs: distinguish between STAR AST and NMRSTAR AST constraints; remove list of error conditions as it's obsolete
improve readme, excising junk