remove garbage from makefiles

Including
* unused FLAGS variables
* All: lib that did not work
* stray blank lines etc

Commit-type: housekeeping
/spend 1h

Docs: bulk add backticks to .seealso man page fields

```python
import os
import re
import fileinput

def _process_word(word):
comma = "," if word.endswith(",") else ""
return "`%s`%s" % (wor

Docs: bulk add backticks to .seealso man page fields

```python
import os
import re
import fileinput

def _process_word(word):
comma = "," if word.endswith(",") else ""
return "`%s`%s" % (word.rstrip(","), comma)

def _process_stripped_line(line):
return " ".join(map(_process_word, line.split()))

start_pattern = re.compile(r"^( *\.seealso:? )(.*$)")

def process_file(filename_full):
with fileinput.FileInput(filename_full, inplace=True) as f:
in_block = False
for line in f:
line_stripped = line.strip()
# end ".seealso blocks" on a blank line or C-style comment close
line_modified = None
if not line_stripped:
in_block = False
elif line_stripped.endswith("*/"):
in_block = False
else:
match = re.match(start_pattern,
line) # not stripped line
if match:
indent = " " * len(match.group(1))
in_block = True
line_modified = match.group(
1) + _process_stripped_line(
match.group(2).strip())
elif in_block:
line_modified = indent + _process_stripped_line(
line_stripped)
if line_modified:
print(line_modified) # prints to the file
else:
print(line, end="") # prints to the file

BASE_DIRS = ["src", "include"]
EXT = [".c", ".cxx", ".cpp", ".cu", ".h", ".hpp", ".hxx"]
EXCLUDE_DIRS = ["tests", "tutorials", "ftn-auto", "ftn-custom", "benchmarks"]

def main():
""" Process everything """
for base in BASE_DIRS:
for root, dirs, files in os.walk(base):
for filename in files:
if os.path.splitext(filename)[1] in EXT:
filename_full = os.path.join(root, filename)
print("FILE ---", filename_full)
process_file(filename_full)
for exclude_dir in EXCLUDE_DIRS:
if exclude_dir in dirs:
dirs.remove(exclude_dir)

if __name__ == "__main__":
main()
```

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