Fixes #1644

Reading of JSON data off the buffer, 10-15% performance increase.

Fixes #1864.

Use process.argv instead.

Some of the perf improvements from many-writes-fix branch were accidentally
undone in that commit. This puts them back in.

Fixes #1869.

fs.readdir() on file should raise ENOTDIR, not UNKNOWN.

Fixes #1857

Fixes #1706.

This removes one of the three build systems. CMake has never been officially
supported and is not updated with WAF and GYP. WAF itself is considered
legacy and will be removed once the GYP system is feature complete on
Unixes. GYP is used currently on Windows/MSVS.