Poetic line markup conversion to MEI

[craigsapp]

Add conversions of poetic line markup in the Humdrum-to-MEI conversion.

Example of markup in Humdrum:

https://docs.google.com/presentation/d/1ud38CybH2O9bOc8C_cvNhG-3RiSCSUXf_rlpnWHR15o/edit#slide=id.g27bb8ab5b8f_0_0

Use the syl@type to encode the information, such as perhaps:

• L3 = the syllable is from line three of the poem.
• N5 = 5th syllable on the line.
• P[123] = The syllable is from an incomplete repetition of the full poetic line: 1=starting at beginning of line. 2=ending at the end of the line, 3=starts and ends in the middle of the line.
• R[A-Za-z] = rhyme scheme for the line, probably only attached to the last syllable of the poetic line. The previous syllable is typically also involved, but not necessarily the beginning consonant of the previous syllable. Small letters are for 7-syllable lines, and upper case for 11-syllable lines. This should be encoded for every .
• T2 = In the second repetition of the line or line fragment (full, and partial line cases treated separatly, such as T2f for cases in a full presentaiton of the poetic line, T2a for a partial presentation from the star, T2b for partial repreat from the end, and T2c for partial repeat of a middle of the text).
• E[12] = E1 on the last syllable of the line indicates and Enjambment is happening (next line is a grammatic continuation of the poetic line). E2 can be added to the first syllable of the next line to indicate the linkage to the previous line.
• S = The syllable has a grammatical stress (poetic stress is slightly different but not (yet) encoded).