Update mot-encoder.cpp

1. apply the default sleepdelay between each slide
2. confine maximum DLS length to the specification.
3. avoid increasing constantly Transport ID
Improved management of Slideshow TID

A slide receives a new TID only when it is completely new, re-transmitted images retain their TID.
Une diapositive recoit un nouveau TID seulement quand elle est complètement nouvelle, les images re-transmises conservent leur TID.
Update mot-encoder.cpp
Update mot-encoder.cpp
Syntax error correction
New fidx management based on slide footprint

footprint = file name + file size + last modification time
Add certain comments
Add file broadcasting mode
Update fidx management
Disable DEBUG by default
Corrections, improvements and style updates

Change the way the database is done (use a deque, save fidx in the
fingerprint, remove cursors, distinguish between history size and
max fidx value)
Rename -f to -R and update explanation
Order slide tranmission by fidx
Correct types in fingerprint_t
Move some fingerprint logic into fingerprint_t
Add additional sleep if DLS disabled and no slide available
Fix intentation and code style