[FIX] Fixing several paths for the core/extras level removal.
[FIX] Removing some problems introduced by the core/extras merging.
[FIX] Fixing yet another search-and-replace bug.
[FIX] Yet another path fix for core/extras merge.
[INTERNAL] replace dddoc with placeholder (automatic)

for FILE in $(ack -l  "\/\*\*" apps include tests); do
awk ' $1 == "/**" { DD = 1; next}; (DD == 1) && (NF > 0) && ($NF == "*/") { DD = 0; print "/*_DDDOC_PLACEHOLDER*/"; next}; DD == 0 { print $0 }' $FILE > ${FILE}.new;
done
for FILE in $(find ./ -name "*.new"); do mv $FILE $(echo $FILE | sed -e 's/\.new//g'); done
[INTERNAL] also replace leftover ddocs with placeholder

 for FILE in $(ack -l  "\/\*\*" apps include tests); do                                                                                                                                      :(
awk ' ($1 == "/**") || ( $1 ~ /^\/\*\*\.Function/ ) { DD = 1; next}; (DD == 1) && (NF > 0) && ($NF == "*/") { DD = 0; print "/*_DDDOC_PLACEHOLDER*/"; next}; DD == 0 { print $0 }' $FILE > ${FILE}.new;
done

for FILE in $(find ./ -name "*.new"); do mv $FILE $(echo $FILE | sed -e 's/\.new//g'); done
[INTERNAL] remove the placeholders and possibly a following blank line

for FILE in $(ack -l DDDOC_PLACEHOLDER); do \
perl -0777 -i -pe 's|\n\/\*\_DDDOC\_PLACEHOLDER\*/\n\n|\n|g' $FILE; \
perl -0777 -i -pe 's|\n\/\*\_DDDOC\_PLACEHOLDER\*/\n|\n|g' $FILE; \
done
[INTERNAL] remove single-line DDOC comments and possibly trailing empty lines

```for FILE in $(ack -l '\/\/\/\.' apps include tests); do awk '$1 ~ /\/\/\/\./ { print "/*_DDDOC_PLACEHOLDER*/"; next }; { print }' $FILE > ${FILE}.new ; done```
```for FILE in $(find ./ -name "*.new"); do mv $FILE $(echo $FILE | sed -e 's/\.new//g'); done```
```for FILE in $(ack -l DDDOC_PLACEHOLDER); do \
perl -0777 -i -pe 's|\n\/\*\_DDDOC\_PLACEHOLDER\*/\n\n|\n|g' $FILE; \
perl -0777 -i -pe 's|\n\/\*\_DDDOC\_PLACEHOLDER\*/\n|\n|g' $FILE; \
done```

had to run last command multiple times to get all instances
Merge pull request #719 from h-2/removeDDDoc

Remove old documentation system