* module/ice-9/peg.scm: rename 'peg-sexp-compile' to
'compile-peg-pattern'
* module/ice-9/peg/codegen.scm: same
* module/ice-9/peg/string-peg.scm: same
* module/ice-9/peg/using-parsers.scm: same
* doc/ref/api-peg.texi: same
* module/ice-9/peg.scm: rename 'define-grammar' to
'define-peg-string-patterns'
* module/ice-9/peg/string-peg.scm: same
* doc/ref/api-peg.texi: same
* test-suite/tests/peg.bench: same
* test-suite/tests/peg.test: same
* module/ice-9/peg.scm: rename 'define-nonterm' to 'define-peg-pattern'
* module/ice-9/peg/using-parsers.scm: same
* module/ice-9/peg/string-peg.scm: same
* test-suite/tests/peg.test: same
* doc/ref/api-peg.texi: same
* module/ice-9/peg.scm: rename 'peg-parse' to 'match-pattern'
* module/ice-9/peg/string-peg.scm: same
* module/ice-9/peg/using-parsers.scm: same
* doc/ref/api-peg.texi: same
* test-suite/tests/peg.test: same
* test-suite/tests/peg.bench: same
* doc/ref/api-peg.texi: rename 'peg-match' to 'search-for-pattern'
* module/ice-9/peg.scm: same
* module/ice-9/peg/using-parsers.scm: same
* test-suite/tests/peg.test: same
* module/ice-9/peg/codegen.scm: Make the PEG syntax extensible, and
move most of the current code generators to the new interface
* doc/ref/api-peg.texi: Document PEG extensions in the PEG Internals
section of the manual