fixed undefined symbol error with new gcc

[mwht]

Proposal of fixing issue #3

• Fixed segmentation fault (tested with LMMS, issue was NULL copyright set crashing the program)

Notice: could not set realtime priority.
VST sync support disabled in your configuration
[1]    2766 segmentation fault (core dumped)  lmms

• Fixed undefined symbol errors both in LV2 and LAPSDA plugins (tested with Audacity, removed inline statements since gcc seem to break the export symbols)

lilv_lib_open(): error: Failed to open library /usr/lib/lv2/bit-crusher.lv2/bit-crusher.so (/usr/lib/lv2/bit-crusher.lv2/bit-crusher.so: undefined symbol: prepare_downsampling_knob)

[unclechu]

@mwht Looks good, I'll test it and merge soon, thanks for the contribution!

[unclechu]

@mwht Released in v0.3, thanks again!