Users can now do the following:
- use DESTDIR to specify another root dir
- use PREFIX to specify another install path except for /usr/local,
e.g. /usr for the system package.
- load custom CFLAGS and LDFLAGS from environment variables
- use CC to specify the C compiler
These features are helpful to package it into Linux Distribution.
Signed-off-by: Coelacanthus <CoelacanthusHex@gmail.com>
Coelacanthus