Contributing update

See merge request !120

Bug fixes & DL dependencies when specified

See merge request !118

- clear the tmp database before and after making changes on it
- fix clear queue. The problem was due of attached databases
- update max id of queue table when reordering it
- fix generate config on first run, there was a missing strcpy...

- error on empty downloaded json file in repo module.
- only accept a json from kurisu/api

- lktmodule.h include correct .c files when building not in static
  module mode
- define the endiannes defines with the integer 1 when ok
- fix lkt_show_config
- fix configure.ac for CFLAGS settings

- separate header and source files for modules
- create a single header for the modules to include
- use the `#define __LKT_MODULE_MAIN_SOURCE__` before including this
  file in the module's mail source file

- update README.md
- update CONTRIBUTING.md / CONTRIBUTORS
- lkt manpage
- update changelog

- download and build dependencies with configure
- add libcurl
- add zlib
- add iconv
- sdl2 without touchscreen
- compile using -fPIC
- add openssl for libcurl

- Update depends.bash
- Compile dependencies with the depends.sh script

- move queue.c as a single header lib. Update Makefiles
- introduce the module's header

- move queue_tmp to :memory:
- fix for correct deletion of content of queue_tmp
- avoid segfault when finalizing an already finalized stmt
- also make things compile with -Wextra
- make things compile again

Hooks

Closes #74

See merge request !116

The queue_end is not used for the moment.
Les hooks sont exécutés que si la commande a réussie.

- edit config to specify hooks
- add function to handle all functions for a hook

Resolve "Config file created by lektord if needed"

Closes #75

See merge request !117

By default, lektor is built with modules inside. The old behaviour was
just painfull.

- Fix the clear to whipe the autoinc ids
- Stop player on clear playlist to avoid desync
  problems and inconsistencies in the queue

Resolve "Incorrect state with command `lkt play`"

Closes #69

See merge request !114

Solves over usage of CPU

See merge request !115

Use the `sleep` function instead of `yield` to really release the CPU.

Refactor and more

See merge request !105