Fixing minor nits for the win.

[Unitrunker]

Built on FreeBSD 11.2 with

./configure --enable-sse --enable-single --prefix=/usr/local

make complained of missing ffts_small.c and patterns.c - removed those from src/Makefile.in
Linker complained of undefined symbols found in ffts_static.c and ffts_trig.c - added those to src/Makefile.in
typo fix in ffts_trig.c
added missing header(s) to test.c (fixed a segfault)

./configure fails to add USE_SYS_MMAN_H to config.h - must do so manually.

Output from tests/test:

Sign | Size | L2 Error
------+-----------+-------------
-1 | 2 | 8.659561E-17
-1 | 4 | 1.145552E-16
-1 | 8 | 1.210162E-08
-1 | 16 | 2.220916E-08
-1 | 32 | 2.396272E-08
-1 | 64 | 2.272872E-08
-1 | 128 | 1.940460E-08
-1 | 256 | 2.081312E-08
-1 | 512 | 2.045939E-08
-1 | 1024 | 2.079071E-08
-1 | 2048 | 2.074052E-08
-1 | 4096 | 2.124981E-08
-1 | 8192 | 2.086463E-08
-1 | 16384 | 2.071494E-08
-1 | 32768 | 2.062090E-08
-1 | 65536 | 2.054694E-08
-1 | 131072 | 2.060355E-08
-1 | 262144 | 2.054523E-08
1 | 2 | 8.659561E-17
1 | 4 | 1.145552E-16
1 | 8 | 1.210162E-08
1 | 16 | 2.220916E-08
1 | 32 | 2.396272E-08
1 | 64 | 2.272872E-08
1 | 128 | 1.940460E-08
1 | 256 | 2.081312E-08
1 | 512 | 2.045939E-08
1 | 1024 | 2.079071E-08
1 | 2048 | 2.074052E-08
1 | 4096 | 2.124981E-08
1 | 8192 | 2.086463E-08
1 | 16384 | 2.071494E-08
1 | 32768 | 2.062090E-08
1 | 65536 | 2.054694E-08
1 | 131072 | 2.060355E-08
1 | 262144 | 2.054523E-08

[Unitrunker]

Some fixes are duplicates of
#60

[Unitrunker]

Disregard this PR. Will submit a new one using CMake that supports clang.

[Unitrunker]

did not know configure / Makefile.in files are no longer maintained.