Changed nloptr.default.options to function.

Previously, nloptr.default.options was a data.frame. As this data was
not exported it results in errors when another package calls nloptr
(which uses nloptr.default.options) while the nloptr package is not
attached. The same data.frame is now return from the exported function
nloptr.get.default.options in order to solve this problem.
Added documentation for nloptr.get.default.options
adding a first and very simple configire.ac / configure script
gross hack: disabled bounds setting for a moment
restoring brute-force test
adding a configure script with build logic taken from the old src/Makevars
remove a possibleremaining nlopt-?.?.?/ build directory
added an entry to ChangeLog
lower Version to 1.0.0.1 as 1.0.0 was the last CRAN release
changed licensing of configure.ac file to GPL-2 with exemption for nloptr
configure now respects two command-line arguments for CFLAGS and LIBS
build matrix with and without libnlop0-dev
corrected conditional logic for Travis build matrix
revert sed use to ed use in building nlopt case
Changed version number
Merge branch 'nloptr-options'

Conflicts:
	CHANGELOG
	DESCRIPTION
Updated version number
Removed CRLF line endings
Fixed bug in documentation.