maint: Clean up implementations of ode45.m, odeget.m, odeset.m. * ode45.m: Match variable names in function to docstring. Don't use '...' line continuation unless strictly necessary. Remove incorrect isa check for inline function. Use '( )' around switch statement test variable. Use printf, rather than fprintf, where possible. * odeget.m: Match variable names in function to docstring. Rephrase error messages to begin with 'odeget:'. Use try/catch blocks to speed up "fast" and "fast_not_empty" code. Use rows() rather than "size (xxx, 1)". Use isempty rather than "size (xxx, 1) == 0". Use printf, rather than fprintf, where possible. Use unwind_protect block in BIST tests to restore warning state. * odeset.m: Match variable names in function to docstring. Use rows() rather than "size (xxx, 1)". Use isempty rather than "size (xxx, 1) == 0". Use printf, rather than fprintf, where possible. Eliminate for loop with cell2struct for odestruct initialization. Introduce temporary vars oldstruct, newstruct to clarify code. Restate some error messages to begin with 'odeset:'. Use cellfun to quickl check that all field inputs are strings. Use unwind_protect block in BIST tests to restore warning state.

syntax: regexp
# The recurrent (^|/) idiom in the regexps below should be understood
# to mean "at any directory" while the ^ idiom means "from the
# project's top-level directory".

# gnulib makes these silly backup files
.~$

# This directory gets created by gnulib during the build. 
# It contains no Octave files.
^libgnu/*

# This directory mostly contains cruft during build time, but it does
# contain some Octave code, so we gotta be a bit more careful about
# what we ignore here
^m4/(?!ax_).+\.m4$

# Emacs tools create these
(^|/)TAGS$
(^|/)semantic.cache$

(/|^)Makefile\.in$
^INSTALL$

^aclocal\.m4$
^build-.*($|/)
^configure$
^autom4te\.cache($|/)
^config\.in\.h$

# e.g. doc/faq/OctaveFAQ.info
#      doc/interpreter/octave.info-4
^doc/.*\.info(-\d)?$

^doc/\w*/stamp-(vti|\d+)$
^doc/\w*/version-\w+\.texi$
^doc/interpreter/images\.mk$

# e.g. liboctave/operators/smx-op-inc.mk
^liboctave/operators/\w+-op-\w+\.mk$

^libinterp/dldfcn/module\.mk$